#UnfoldTheUniverse #JWST James Webb Space Telescope / Henrietta Leavitt Teleskop
2021-12-25 13:20 - 2031-12-25 17:00 (Europe/Amsterdam)
The James Webb Space Telescope (JWST or “Webb” / called Henrietta Leavitt Teleskop by german scientists Harald Lesch and Josef M. Gaßner) is a space telescope to succeed the Hubble Space Telescope as NASA‘s flagship astrophysics mission.
The JWST will provide improved infrared resolution and sensitivity over Hubble, and will enable a broad range of investigations across the fields of astronomy and cosmology, including observing some of the most distant events and objects in the universe, such as the formation of the first galaxies. The primary mirror of the JWST, the Optical Telescope Element, is composed of eighteen 1.32 metres hexagonal mirror segments made of gold-plated beryllium which combine to create a 6.5 metres diameter mirror that is considerably larger than the Hubble’s 2.4 metres mirror. Unlike the Hubble, which observes in the near ultraviolet, visible, and near infrared (0.1 to 1 μm) spectra, the JWST will observe in a lower frequency range, from long-wavelength visible light through mid-infrared (0.6 to 28.3 μm), which will allow it to observe high redshift objects that are too old and too distant for the Hubble to observe.
The telescope must be kept very cold in order to observe in the infrared without interference, so it will be deployed in space near the Earth–Sun L2 Lagrangian point, and a large sunshield made of silicon-coated and aluminium-coated Kapton will keep its mirror and instruments below 50 Kelvin (K). The JWST is being developed by NASA — with significant contributions from the European Space Agency and the Canadian Space Agency — and is named for James E. Webb, who was the administrator of NASA from 1961 to 1968 and played an integral role in the Apollo program. The prime contractor is Northrop Grumman. Development began in 1996 for a launch that was initially planned for 2007 and a 500-million-dollar budget, but the project has had numerous delays and cost overruns, and underwent a major redesign in 2005. The JWST’s construction was completed in late 2016, after which its extensive testing phase began. The launch date was Dec. 25, 2021.

Links:
James Webb Space Telescope
James Webb Space Telescope -ESA
Webb Home
Webb Space Telescope
NASA’s James Webb Space Telescope – Flickr
JADES will go deeper than the Hubble Deep Fields
James Webb Space Telescope / Henrietta Leavitt Teleskop – playlist
NASA’s Webb In Full Focus, Ready for Instrument Commissioning
Nieuwe ruimtetelescoop kijkt naar het begin van de tijd – of net ietsje later
Webb is now orbiting L2
Photons Received: Webb Sees Its First Star – 18 Times
NASA emails reveal internal discussions over calls to rename James Webb Space Telescope: report
First Images From NASA’s Webb Space Telescope Coming Soon
No, the Big Bang theory is not ‘broken.’ Here’s how we know
Webb Looks for Fomalhaut’s Asteroid Belt and Finds Much More
James Webb spot monsterachtige waterpluim op Enceladus
Webb Space Telescope’s First Year of Science Celebration
Webb Discovers Methane, Carbon Dioxide in Atmosphere of K2-18 b
NASA’s James Webb Space Telescope (Flickr)
The (Unofficial) JWST Exoplanet Dashboard
JWST facing potential cuts to its operational budget
Strongest hints yet of biological activity outside the solar system / New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI – publication

Surface Water and Ocean Topography (SWOT) mission
2022-12-16 - 2025-12-16
The Surface Water and Ocean Topography (SWOT) mission is a satellite altimeter jointly developed and operated by NASA and CNES, the French space agency, in partnership with the Canadian Space Agency (CSA) and UK Space Agency (UKSA).
The objectives of the mission are to make the first global survey of the Earth’s surface water, to observe the fine details of the ocean surface topography, and to measure how terrestrial surface water bodies change over time. While past satellite missions like the Jason series altimeters (TOPEX/Poseidon, Jason-1, Jason-2, Jason-3) have provided variation in river and lake water surface elevations at select locations, SWOT will provide the first truly global observations of changing water levels, stream slopes, and inundation extents in rivers, lakes, and floodplains. In the world’s oceans, SWOT will observe ocean circulation at unprecedented scales of 15–25 km (9.3–15.5 mi), approximately an order of magnitude finer than current satellites. Because it uses wide-swath altimetry technology, SWOT will almost completely observe the world’s oceans and freshwater bodies with repeated high-resolution elevation measurements, allowing observations of variations.
Links:
Surface Water and Ocean Topography at NASA.gov
Ocean Surface Topography from Space at NASA.gov
Cnes project Library at CNES.fr
AVISO+ portal for SWOT

JUpiter ICy moons Explorer
2023-04-13 14:15 - 2035-12-13 17:00
The JUpiter ICy moons Explorer (JUICE) is an interplanetary spacecraft in development by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor.
The mission will study three of Jupiter‘s Galilean moons: Ganymede, Callisto, and Europa, all of which are thought to have significant bodies of liquid water beneath their surfaces, making them potentially habitable environments. The mission is not focused on volcanically active Io, a non-icy moon. The spacecraft launched on 14 April 2023 at 12:14 UTC and will reach Jupiter in July 2031 after four gravity assists and eight years of travel. In December 2034, the spacecraft will enter orbit around Ganymede for its close up science mission, becoming the first spacecraft to orbit a moon other than the Moon of Earth. The selection of this mission for the L1 launch slot of ESA’s Cosmic Vision science programme was announced on 2 May 2012. Its period of operations will overlap with NASA‘s Europa Clipper mission, launching in 2024.

NASA’s Juno Is Getting Ever Closer to Jupiter’s Moon Io Links:
ESA’s JUICE
Juice
Agenda – JUpiter ICy moons Explorer : launch / Agenda – JUpiter ICy moons Explorer : launch 2nd attempt
Juice pre-launch press briefing
How to follow the Juice launch live

Cosmic Vision : Euclid space telescope / Euclides
2023-07-01 17:11 - 2029-07-01 17:11
Euclid is a visible to near-infrared space telescope developed by the European Space Agency (ESA) and the Euclid Consortium, the objective of the Euclid mission is to better understand dark energy and dark matter by accurately measuring the acceleration of the universe.
To achieve this, the Korsch-type telescope will measure the shapes of galaxies at varying distances from Earth and investigate the relationship between distance and redshift. Dark energy is generally accepted as contributing to the increased acceleration of the expanding universe, so understanding this relationship will help to refine how physicists and astrophysicists understand it. Euclid’s mission advances and complements ESA’s Planck telescope (2009 to 2013). The mission is named after the ancient Greek mathematician Euclid. Euclid is a medium-class (“M-class”) mission and is part of the Cosmic Vision campaign of ESA’s Science Programme. This class of missions have an ESA budget cap at around €500 million. Euclid was chosen in October 2011 together with Solar Orbiter, out of several competing missions. Prior to the Russian invasion of Ukraine, the launch was scheduled on a Soyuz ST-B in 2023; following the invasion, Euclid will instead be launched on a Falcon 9 Block 5 on 1 July 2023.
Links:
Euclid
How to follow the Euclid launch live
Ruimtetelescoop Euclid wil uitvinden waar het heelal van gemaakt is
Euclid test images tease of riches to come
Euclid ‘dark universe’ telescope team will unveil new full-color images today (May 23)
Zoom into the first page of ESA Euclid’s great cosmic atlas
Space Warps – ESA Euclid / Euclid Galaxy Zoo – help us classify the shapes of galaxies

Plankton, Aerosol, Cloud, ocean Ecosystem
2024-02-08 07:33 - 2027-02-08 17:00
Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) is a NASA Earth-observing satellite mission that will continue and advance observations of global ocean color, biogeochemistry, and ecology, as well as the carbon cycle, aerosols and clouds.
PACE will be used to identify the extent and duration of phytoplankton blooms and improve understanding of air quality. These and other uses of PACE data will benefit the economy and society, especially sectors that rely on water quality, fisheries and food security. After being proposed for cancellation under President Trump’s FY 2018 budget, it was restored by Congress. The PACE project is managed by NASA Goddard Space Flight Center. The main instrument and bus were designed and built at Goddard Space Flight Center. On 4 February 2020, NASA announced the selection of SpaceX to launch PACE on a Falcon 9, at a total cost to NASA of US$80.4 million, including the launch service and other mission-related costs. The total cost of the mission is $964 million, which includes spacecraft construction, launch, and operations. PACE successfully launched on 8 February 2024 at 07:33.
Links:
PACE

GOES-19
2024-06-25 23:26 - 2039-10-25 00:00
GOES-19 (designated GOES-U prior to reaching geostationary orbit) is a weather satellite, the fourth and last of the GOES-R series of satellites operated by the National Oceanic and Atmospheric Administration (NOAA).
The GOES-R series will extend the availability of the Geostationary Operational Environmental Satellite (GOES) system until 2036. The satellite is built by Lockheed Martin, based on the A2100 platform. The satellite was successfully launched into space atop a SpaceX Falcon Heavy rocket on 25 June 2024 at 21:26 UTC from the Kennedy Space Center in Florida, United States. The redesign of the loop heat pipe to prevent an anomaly, as seen in GOES-17, is not expected to delay the launch as it did with GOES-T. GOES-U also carries a copy of the Naval Research Laboratory‘s Compact CORonagraph (CCOR) instrument which, along with the CCOR planned for Space Weather Follow On-Lagrange 1 (SWFO-L1), will allow continued monitoring of solar wind after the retirement of the NASA–ESA SOHO satellite in 2025. GOES-U has a dry mass of 2,925 kg and a fueled mass of 5,000 kg.
Links:
GEOS – R

GOES-U Mission Overview
Satellite: GOES-19
Watch sun erupt in 1st images from NOAA’s groundbreaking new satellite (photos)

Proba-3 Missie / Proba-3 Mission
2024-09-01 - 2029-09-01
By ESA, CC BY-SA 3.0 igo
Proba-3 zijn twee minisatellieten van de Europese Ruimtevaartorganisatie (ESA), ze zullen samen gelanceerd worden in een langgerekte ellipsvormige baan met een perigeum van 600 km en apogeum van 60.000 km.
Proba-3 wordt gerealiseerd door een consortium van vijftien ESA-lidstaten met als hoofdaannemer het Spaanse SENER, het Belgische Centre Spatial uit Luik als hoofdaannemer voor de coronagraaf en het Belgische Redwire Space voor assemblage en testen. Tijdens de missie zullen twee satellieten in formatie vliegen en samen een 144 meter lange zonnecoronagraaf vormen om de corona van de zon bij de zonnerand te bestuderen. Eén ruimtevaartuig zal de optische telescoop dragen en het tweede ruimtevaartuig zal een deel van de coronagraaf dragen. Tevens worden tijdens deze missie metingen uitgevoerd voor de positionering van twee ruimtevaartuigen.
Links:
Proba-3 Mission

Hera space mission
2024-10-07 16:52 - 2026-12-31 23:59
Hera is a space mission in development at the European Space Agency in its Space Safety program, its primary objective is to study the Didymos binary asteroid system that was impacted by DART and contribute to validation of the kinetic impact method to deviate a near-Earth asteroid in a colliding trajectory with Earth.
It will measure the size and the morphology of the crater created by and momentum transferred by an artificial projectile impacting an asteroid, which will allow measuring the efficiency of the deflection produced by the impact. It will also analyze the expanding debris cloud caused by the impact. The spacecraft was launched on 7 October 2024 and will also study the results of DART impactor, four years after NASA’s mission. DART impacted the asteroid Dimorphos, the smaller of two objects forming the binary asteroid 65803 Didymos, on 27 September 2022. Hera has a mass of 1128 kilograms and carries a payload of cameras, an altimeter, and a spectrometer. It will also carry two nano-satellite CubeSats, called Milani and Juventas. Hera will fully characterise the composition and physical properties of the binary asteroid system including, for the first time, the sub-surface and internal structures. It will also perform technological demonstrations linked to operations in the vicinity of a small body and the deployment and the communication with CubeSats in interplanetary space.
Hera’s launch kit, click picture to read
Links:
ESA Hera
Thermophysical Modelling of Eclipse and Occultation Events in Binary Asteroid Systems
Planetary defence mission Hera heading for deflected asteroid
SpaceX rocket launches Europe’s Hera planetary defense probe to visit asteroid smacked by NASA

NASA’s Europa Clipper Mission
2024-10-14 12:06 - 2030-10-14 23:59
Europa Clipper (previously known as Europa Multiple Flyby Mission) is a space probe in development by NASA.
Planned for launch aboard a Falcon Heavy in October 2024 (the 21-day launch window period opens on October 10, 2024), the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter, it is the largest spacecraft NASA has ever developed for a planetary mission. This mission is a scheduled flight of the Planetary Science Division, designated a Large Strategic Science Mission, and funded under the Planetary Missions Program Office‘s Solar System Exploration program as its second flight. It is also supported by the new Ocean Worlds Exploration Program. Europa Clipper will perform follow-up studies to those made by the Galileo spacecraft during its eight years (1995 – 2003) in Jupiter orbit, which indicated the existence of a subsurface ocean underneath Europa’s ice crust. Plans to send a spacecraft to Europa were initially conceived with projects such as Europa Orbiter and Jupiter Icy Moons Orbiter, in which a spacecraft would be injected into orbit around Europa. However, due to the adverse effects of radiation from Jupiter’s magnetosphere in Europa orbit, it was decided that it would be safer to inject a spacecraft into an elliptical orbit around Jupiter and make 44 close flybys of the moon instead. The mission began as a joint investigation between the Jet Propulsion Laboratory (JPL) and the Applied Physics Laboratory (APL), and will be built with a scientific payload of nine instruments contributed by JPL, APL, Southwest Research Institute, University of Texas at Austin, Arizona State University and University of Colorado Boulder. The upcoming mission complements ESA‘s Jupiter Icy Moons Explorer launched in 2023, which will fly-by Europa twice and Callisto multiple times before moving into orbit around Ganymede. The spacecraft will use gravity assists from Mars in February 2025 and Earth in December 2026, before arriving at Europa in April 2030. NASA will provide live coverage of prelaunch and launch activities for Europa Clipper, the agency’s mission to explore Jupiter’s icy moon Europa. NASA now is targeting launch no earlier than 18:06 CEST, Monday, Oct. 14, on a SpaceX Falcon Heavy rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida.
Links:
NASA’s Europa Clipper Mission
Europa Clipper
The search for life on Jupiter’s moon Europa – the Europa Clipper Mission
8 Things to Know About NASA’s Mission to an Ocean Moon of Jupiter
NASA, SpaceX Secure Europa Clipper Ahead of Hurricane (Milton)

#Hubble35 Hubble Telescope – 35th Anniversary Hubble’s Night Sky Challenge
2025-01-01 - 2025-12-31
Hubble is working with The Astronomical League to coordinate the “Hubble’s Night Sky Observing Challenge” program, providing successful observers with recognition of their achievements.
The challenge includes two levels and observers do not need to be an Astronomical League member to participate. Do you have a telescope? Would you like to see some of the same night sky objects from the ground that Hubble has from space? You are invited to commemorate Hubble’s 35th anniversary by accepting our year-long stargazing challenge. New challenge objects will be featured weekly. On a clear night, find a safe location with a dark sky away from bright lights, point your telescope skyward, and with the help of star and finder charts, gaze upon some of the same iconic nebulae and galaxies Hubble has observed. How many of them can you find? For amateur astronomy clubs, science centers, museums, and other astronomy enthusiasts, use these monthly lists as a guide to conduct star parties that provide an opportunity for the public to see some amazing astronomical objects in person.
Links:
Hubble’s Night Sky Challenge

Save the Observatory Science Centre Herstmonceux - petition
2025-01-10 - 2026-12-31
The Observatory Science Centre is an educational charity which has called the Grade II listed, former home of the Royal Greenwich Observatory at Herstmonceux, East Sussex, home for the last 30 years.
The Canadian landlords, Queen’s University, who also own Herstmonceux Castle, are not renewing the Science Centre’s lease, so come the end of the 2026 season the Science Centre will be homeless. Over the years the science centre have worked tirelessly to fund and restore the site and the telescopes back to their former glory. The centre is a major venue for exhibitions, lectures and educational programmes. The renovated telescopes provide a unique setting for the general public, schools, colleges, and brownie and scout groups to learn about science, space and the world around them. Whilst the Science Centre is in search for a new site to continue operations beyond 2026, they should not have to leave the Observatory site at all and the historic site should be preserved for future generations as a great educational tool of significant historical importance. Please sign this petition for someone to step in and prevent the Science Centre from having to leave the Observatory site.
Links:
Save the Observatory Science Centre Herstmonceux
Herstmonceux Observatory Campaign Group

Landelijke Sterrenkijkdagen 2025
2025-03-07 - 2025-03-09 | Nederland, Nederland
De Nederlandse sterrenwachten, planeteria en amateursterrenkundigen organiseren elk jaar de Landelijke Sterrenkijkdagen, belangstellenden krijgen de kans om met eigen ogen door telescopen naar hemellichamen te kijken.
Bij slecht weer is er een alternatief programma met lezingen, exposities, dia’s en informatie over sterrenkunde als hobby. De meeste sterrenwachten, een aantal Koninklijke Nederlandse Vereniging voor Weer- en Sterrenkunde (KNVWS) afdelingen en andere enthousiaste amateurs stellen in dat weekend hun deuren open om het geïnteresseerde publiek te laten kennismaken met sterrenkunde. Stichting ‘De Koepel’ te Utrecht was de coördinator van de landelijke Sterrenkijkdagen, vanaf 2014 is de KNVWS de coördinator.
Links:
Landelijke Sterrenkijkdagen
Landelijke Sterrenkijkdagen op 7, 8 en 9 maart 2025

Sporadic radio pulses from a white dwarf binary at the orbital period - publication
2025-03-12
In the past three years, astronomers have discovered a mysterious new type of radio source called these long period transients.
These objects emit bright radio signals that repeat every few minutes to every few hours. The astronomers have found about a dozen examples, but we still don’t understand which type of star could emit radio pulses in this peculiar way. In the research ‘Sporadic radio pulses from a white dwarf binary at the orbital period‘, the astronomers have discovered a new long period transient. Furthermore, they identified the stars responsible for the mysterious radio flashes – a breakthrough never achieved before.
Links:
Mysterious radio pulses from space have been tracked down – and the source is not what astronomers expected

Totale maansverduistering op 14 maart 2025
2025-03-14 07:26 - 08:33
Op vrijdag 14 maart 2025 vindt een totale maansverduistering plaats, een maansverduistering doet zich voor wanneer de Zon, de Aarde en de Maan op één lijn staan (met de Aarde in het midden), oftewel als Zon en Maan in oppositie staan.
Normaal weerkaatst de maan het licht van de zon naar de Aarde, maar tijdens een maansverduistering staat de aarde in de weg en ontvangt de Maan geen zonlicht: de Maan bevindt zich in de schaduw van de aarde en wordt dus donker, ofwel verduisterd. Maansverduisteringen treden in een patroon op. Deze zogenaamde Saros-cyclus herhaalt zich elke 18 jaar. In de Benelux is alleen het begin van de eclips zichtbaar. De verduistering heeft een grootte van 1.18 in de kernschaduw. Tijdens de totaliteit, die duurt van 07:26 tot 08:33, bevindt de Maan zich volledig in de kernschaduw van de Aarde en valt er geen direct zonlicht meer op de Maan. Echter, een beetje zonlicht valt door de aardatmosfeer en wordt gebroken, waardoor dit het maanoppervlak alsnog kan bereiken. Dit is met name rood licht, waardoor er een rode gloed over de Maan komt. Deze fase wordt in de volksmond ook wel Bloedmaan genoemd, en duurt bij deze eclips circa 67 minuten.
Links:
Totale maansverduistering op 14 maart 2025
The Next Full Moon is the Worm Moon
What to know about this week’s ‘blood worm moon’ total lunar eclipse
The Worm “Blood” Moon: Full Moon for March 2025

World Contact Day 2025
2025-03-15
World Contact Day was first declared in March 1953 by an organization called the International Flying Saucer Bureau (IFSB), as a day on which all IFSB members would attempt to send a telepathic message into space.
The IFSB voted to hold such a day in 1953, theorising that if both telepathy and alien life were real, a large number of people focussing on an identical piece of text may be able to transmit the message through space. IFSB members focused on the following message during 1953:
Calling occupants of interplanetary craft! Calling occupants of interplanetary craft that have been observing our planet EARTH. We of IFSB wish to make contact with you. We are your friends, and would like you to make an appearance here on EARTH. Your presence before us will be welcomed with the utmost friendship. We will do all in our power to promote mutual understanding between your people and the people of EARTH. Please come in peace and help us in our EARTHLY problems. Give us some sign that you have received our message. Be responsible for creating a miracle here on our planet to wake up the ignorant ones to reality. Let us hear from you. We are your friends.
The 1953 celebration is referenced in the song “Calling Occupants of Interplanetary Craft“, created in 1976 by Klaatu and later covered by The Carpenters.
Links:
Klaatu Track Facts
World Contact Day brings together E.T. enthusiasts from all over the world

JWST-TST High Contrast: Living on the Wedge, or, NIRCam Bar Coronagraphy Reveals CO2 in the HR 8799 and 51 Eri Exoplanets' Atmospheres - publication
2025-03-17
Astronomers have announced that the James Webb Space Telescope (JWST) has successfully captured its first direct images of carbon dioxide gas on a planet beyond the solar system, the findings are both a testament to the telescope’s power in direct imaging and provide valuable insights into how planets form, both within our solar system and across the universe.
The latest JWST observations focused on the HR 8799 system, which consists of four planets orbiting their host star about 130 light-years from Earth in the constellation Pegasus. Previous observations have shown four of them are more massive than Jupiter, and are in orbits with periods that range from decades to centuries. This system has long intrigued astronomers studying planet formation, largely because of its youth — at just 30 million years old, these planets still radiate leftover heat from their births, which JWST was able to observe in wavelengths that tease out the specific gases and other atmospheric details.
Links:
James Webb Space Telescope sees four giant alien planets circling nearby star

New DESI Results Strengthen Hints That Dark Energy May Evolve - publication
2025-03-19
The Dark Energy Spectroscopic Instrument (DESI) collaboration published an analysis of dark energy using their first three years of collected data, which spans nearly 15 million galaxies and quasars.
Researchers combined the DESI data with information from studies of the cosmic microwave background, supernovae, and weak gravitational lensing. The standard model of cosmology struggles to explain all the observations when taken together — but a model where dark energy’s influence changes over time seems to fit the data well. DESI is an international experiment with more than 900 researchers from over 70 institutions around the world and is managed by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The collaboration shared their findings in multiple papers that will be posted on the online repository arXiv and in a presentation at the American Physical Society’s Global Physics Summit in Anaheim, California.
Links:
New DESI Results Strengthen Hints That Dark Energy May Evolve

Babelsberger Sternennächte – Sterne im Computertomographen | Dr. Axel Schwope (TV webcast)
2025-03-20 20:00 - 21:00
Die Leibniz-Instituts für Astrophysik Potsdam (AIP) Babelsberger Sternennächte finden online statt, in der Regel gibt es immer am 3. Donnerstag im Monat einen neuen Vortrag einer Wissenschaftlerin oder eines Wissenschaftlers des AIP, der ab 20 Uhr auf dem YouTube-Kanal von Urknall, Weltall und das Leben ausgestrahlt wird.
Links:
Babelsberger Sternennächte
Babelsberger Sternennächte – playlist

Can rotation solve the Hubble Puzzle? - publicatie
2025-03-21
A slowly spinning universe could solve the Hubble tension.
The study ‘Can rotation solve the Hubble Puzzle?‘ in Monthly Notices of the Royal Astronomical Society by researchers including István Szapudi of the University of Hawaiʻi at Mānoa Institute for Astronomy suggests the universe may rotate—just extremely slowly. The finding could help solve one of astronomy’s biggest puzzles. Current models say the universe expands evenly in all directions, with no sign of rotation. This idea fits most of what astronomers observe. But it doesn’t explain the so-called Hubble tension—a long-standing disagreement between two ways of measuring how fast the universe is expanding.
Links:
A slowly spinning universe could solve the Hubble tension
Een langzaam roterend heelal zou de Hubble spanning kúnnen oplossen

Livestream VSB -- Oneindigheid (TV webcast)
2025-03-21 20:00 - 22:00
Onmeetbaar en niet waarneembaar: oneindigheid is misschien wel één van de meest fascinerende concepten in de natuurwetenschap en filosofie.
“Hoe kan het heelal oneindig zijn?” is een vraag die het publiek ons met regelmaat stelt. Wat bedoelen astronomen met oneindig en hoe komen ze op dat idee? Christiaan Schriks neemt u mee om op deze onmogelijke, ongrijpbare en onvoorstelbare vraag toch iets van een ‘antwoord’ te geven.
Links:
Oneindigheid

Moon Dust to Mars Dreams: The Next Step Beyond Earth (TV webcast)
2025-03-21 21:00 - 22:00
Astronaut Woody Hoburg and leading planetary scientists join Brian Greene to explore ambitious new missions set to propel humanity deeper into space and sharpen our quest to discover life beyond Earth. This program is part of the Big Ideas series.
Links:
Moon Dust to Mars Dreams: The Next Step Beyond Earth

Witnessing the onset of reionization through Lyman-α emission at redshift 13 - publication
2025-03-26
Using the unique infrared sensitivity of NASA’s James Webb Space Telescope, researchers can examine ancient galaxies to probe secrets of the early universe.
An international team of astronomers has identified bright hydrogen emission from a galaxy in an unexpectedly early time in the universe’s history. The surprise finding is challenging researchers to explain how this light could have pierced the thick fog of neutral hydrogen that filled space at that time. The Webb telescope discovered the incredibly distant galaxy JADES-GS-z13-1, observed to exist just 330 million years after the big bang, in images taken by Webb’s NIRCam (Near-Infrared Camera) as part of the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES). Researchers used the galaxy’s brightness in different infrared filters to estimate its redshift, which measures a galaxy’s distance from Earth based on how its light has been stretched out during its journey through expanding space. The NIRCam imaging yielded an initial redshift estimate of 12.9. Seeking to confirm its extreme redshift, an international team lead by Joris Witstok of the University of Cambridge in the United Kingdom, as well as the Cosmic Dawn Center and the University of Copenhagen in Denmark, then observed the galaxy using Webb’s Near-Infrared Spectrograph instrument. In the resulting spectrum, the redshift was confirmed to be 13.0.
This equates to a galaxy seen just 330 million years after the big bang, a small fraction of the universe’s present age of 13.8 billion years old. But an unexpected feature stood out as well: one specific, distinctly bright wavelength of light, known as Lyman-alpha emission, radiated by hydrogen atoms. This emission was far stronger than astronomers thought possible at this early stage in the universe’s development. Before and during the era of reionization, the immense amounts of neutral hydrogen fog surrounding galaxies blocked any energetic ultraviolet light they emitted, much like the filtering effect of colored glass. Until enough stars had formed and were able to ionize the hydrogen gas, no such light — including Lyman-alpha emission — could escape from these fledgling galaxies to reach Earth. The confirmation of Lyman-alpha radiation from this galaxy, therefore, has great implications for our understanding of the early universe. The source of the Lyman-alpha radiation from this galaxy is not yet known, but it may include the first light from the earliest generation of stars to form in the universe. A powerful active galactic nucleus, driven by one of the first supermassive black holes, is another possibility identified by the team.
Links:
NASA’s Webb Sees Galaxy Mysteriously Clearing Fog of Early Universe

Gedeeltelijke Zonsverduistering van 29 maart 2025 / Partial Solar Eclipse
2025-03-29 11:17 - 13:04
Een zonsverduistering (of zoneclips) is een astronomisch verschijnsel waarbij de maan vanuit de aarde gezien de zon geheel of gedeeltelijk bedekt.
Zonsverduisteringen vinden plaats als de Aarde, Maan en Zon vrijwel op een lijn staan, met de Maan in het midden. Een zonsverduistering kan slechts op een deel van de Aarde worden waargenomen. De schaduw van de Maan vormt (min of meer) een ellips op het aardoppervlak, maar zal (min of meer) cirkelvormig zijn wanneer de schaduwkegel haaks op het aardoppervlak staat. Een totale verduistering is te zien waar de slagschaduw, dit wordt ook wel kernschaduw of umbra genoemd, van de Maan het aardoppervlak raakt. Er is dan sprake van een totaliteitszone. Een gedeeltelijke verduistering is te zien waar de halfschaduw, die ook wel penumbra genoemd wordt, van de Maan het aardoppervlak raakt. Bij deze laatste is er slechts een hap zichtbaar uit de Zon. Niet bij elke zonsverduistering raakt de kernschaduw van de Maan de Aarde; in dat geval is er nergens op aarde een totale verduistering te zien, maar enkel een gedeeltelijke. Een ringvormige zonsverduistering is een bijzondere variant van een gedeeltelijke zonsverduistering. De baan van de Maan om de Aarde is niet precies cirkelvormig, waardoor de Maan soms iets dichter bij, soms wat verder af van de Aarde staat. In het laatste geval kan het voorkomen dat de Maan slechts het middelste gedeelte van de Zon afdekt. Er is dan een ringvormige zonsverduistering te zien. Een bijzonder soort zonsverduistering doet zich voor wanneer een zonsverduistering in bepaalde gebieden totaal is en in andere gebieden als ringvormig wordt waargenomen. Er is dan sprake van een ringvormige/totale of hybride zonsverduistering.
Op zaterdag 29 maart 2025, tussen 11:17 en 13:04, vindt een gedeeltelijke zonsverduistering plaats. Bij helder weer zal vanuit Nederland en België de hele verduistering zichtbaar zijn. Je ziet de eclips als een hap die in eerste instantie uit de rechterkant van de Zon wordt genomen en steeds groter wordt. Halverwege de verduistering bevindt die hap zich aan de bovenkant, en tegen het einde van de eclips verdwijnt deze aan de linkerkant van de Zon. De verduistering duurt in de Benelux 1,8 uur. Tijdens het maximum van de eclips, om 12:10, zal 36% van de diameter van de Zon, ofwel 24% van haar oppervlakte, bedekt zijn. De Zon staat op dat moment 41° boven de zuidzuidoostelijke horizon en het maximum van de eclips is in onze streken goed zichtbaar. Aangezien de Maan ten noorden langs de Zon trekt, wordt de verduistering groter naarmate je je noordelijker bevindt. Zie de lokale gegevens voor een aantal plaatsen in de Benelux. Een bedekking van 24% is niet voldoende om het donker te maken in onze streken, maar meer dan genoeg om te worden opgemerkt met het blote oog (zonder vergroting, maar met bescherming). Daarnaast heeft de reductie aan zonlicht invloed op bijvoorbeeld de energieopwekking door zonnepanelen.
Links:
Partial Solar Eclipse Watch
Zonsverduistering van 29 maart 2025
Zonsverduistering op 29 maart 2025
Gedeeltelijke zonsverduistering
NASA website met historische en toekomstige verduisteringen
Interactive Google Maps over zonsverduisteringen
Zonsverduistering 2025 – Wat is het en wanneer vindt de volgende plaats?
Volkssterrenwacht Bussloo – Speciale openstelling

#GAM2025 Global Astronomy Month 2025
2025-04-01 - 2025-04-30
Inspired by the 100 hours of astronomy, this annual offshoot began upon the inception of Astronomers Without Borders and remains one of its flagship programs.
A mix of various programs ranging from Astro Arts to Observational Programs, this festival runs the whole month of April and features partners that creates a larger community of astronomy enthusiasts that span the globe.
Links:
Global Astronomy Month 2025

Babelsberger Sternennächte – Hunting for hidden X-ray treasures in Space | Dr. Iris Traulsen (TV webcast)
2025-04-01 20:00 - 21:00
Die Leibniz-Instituts für Astrophysik Potsdam (AIP) Babelsberger Sternennächte finden online statt, in der Regel gibt es immer am 3. Donnerstag im Monat einen neuen Vortrag einer Wissenschaftlerin oder eines Wissenschaftlers des AIP, der ab 20 Uhr auf dem YouTube-Kanal von Urknall, Weltall und das Leben ausgestrahlt wird.
Dr. Iris Traulsen nimmt das Publikum mit „Auf die Suche nach den Röntgenstrahlern im All“. Mit der überraschenden Entdeckung von Röntgenstrahlen aus dem Weltraum in den 1960er Jahren und der folgenden Entwicklung von astronomischen Röntgendetektoren öffnete sich ein neues Fenster ins Universum: Im Röntgenlicht sind energiereiche, exotische Prozesse zu sehen. Dieses “kosmische Labor” lässt uns noch unbekannte Eigenschaften bereits bekannter astronomischer Objekte wie auch noch unbekannte Arten von Objekten entdecken. Die Europäische Weltraumagentur ESA betreibt die große satellitengestützte Röntgenmission XMM-Newton, die seit Januar 2000 wissenschaftliche Beobachtungen durchführt. Seit etwa 20 Jahren arbeitet Iris Traulsen mit den XMM-Newton-Daten und berichtet, dass sich darin viele noch unbekannte astronomische Röntgenstrahler verbergen. Wie lassen sich diese aufspüren und für die Wissenschaft zugänglich machen? Der Vortrag lädt dazu ein, ins wissenschaftliche Team hinter den Kulissen eines Weltraumteleskops zu blicken und tiefer ins “heiße Universum“ einzutauchen.
Links:
Babelsberger Sternennächte
Babelsberger Sternennächte – playlist

#HumanSpaceFlightDay / Dag van de Ruimtevaart 2025
2025-04-12
The UN General Assembly, in its resolution A/RES/65/271 of 7 April 2011, declared 12 April as the International Day of Human Space Flight “to celebrate each year at the international level the beginning of the space era for mankind, reaffirming the important contribution of space science and technology in achieving sustainable development goals and increasing the well-being of States and peoples, as well as ensuring the realization of their aspiration to maintain outer space for peaceful purposes.”
12 April 1961 was the date of the first human space flight, carried out by Yuri Gagarin, a Soviet citizen. This historic event opened the way for space exploration for the benefit of all humanity. The General Assembly expressed its deep conviction of the common interest of mankind in promoting and expanding the exploration and use of outer space, as the province of all mankind, for peaceful purposes and in continuing efforts to extend to all States the benefits derived there from.
Links:
Day of Human Space Flight 12 April
World Space Week

The Sky at Night – Asteroid Strike? (TV BBC Four)
2025-04-14 23:00 - 23:30
The Sky at Night is a monthly documentary television programme on astronomy produced by the BBC.
The show had the same permanent presenter, Patrick Moore, from its first broadcast on 24 April 1957 until 7 January 2013. The latter date was a posthumous broadcast, which followed Moore’s death on 9 December 2012. This made it the longest-running programme with the same presenter in television history. Many early episodes are missing, either because the tapes were wiped, thrown out, or because the episode was broadcast live and never recorded in the first place. Beginning with the 3 February 2013 edition, the show was co-presented by Lucie Green and Chris Lintott. Since December 2013 Maggie Aderin-Pocock has been a presenter. The programme’s opening and closing theme music is “At the Castle Gate”, from the incidental music to Pelléas et Mélisande, written in 1905 by Jean Sibelius, performed by the Royal Philharmonic Orchestra and conducted by Sir Thomas Beecham.
This episode:
The team explore one of the biggest stories in space news, the ‘city killer’ asteroid 2024 YR4. First observed on 27 December 2024, it soon became one of the biggest threats from an asteroid ever detected, with the potential to cause a heat blast that could vaporise solid rock, wind blasts five times the speed of the strongest hurricane and a shockwave that would flatten buildings and trees for hundreds of miles. This was a potential natural disaster we needed to respond to as a planet. So how well did we do? Our team of presenters are on hand to find out, and while YR4 was later downgraded to a near miss, what has it told us about our ability to react when an asteroid strike is on its way? George Dransfield kicks off, talking us through the damage an asteroid like YR4 could do and why some say we are overdue an asteroid strike of this size. But how will we know if it’s truly on its way? Chris Lintott meets Dr Meg Schwamb at a football pitch – which it turns out is the perfect place to explain how the probability of a strike is calculated. Following the same highs and lows they do when a ball just misses the goal, they explain why the probability of asteroid 2024 YR4 hitting earth first rose so quickly before it fell. It turns out it wasn’t the maths being wrong!
Luckily, next time the numbers say an asteroid impact is on its way, we do have ways of defending ourselves, Maggie Aderin-Pocock takes a tea break to explain some of the options, from nudging it to nuking it – they all have their pros and cons. But to know our best plan of action, we need to understand more about the asteroids, and George meets up with Dr Carly Howett to find out how Nasa’s Lucy Mission could provide us with invaluable information for any future strikes. With this wealth of information about any potential asteroids heading our way, Maggie meets Prof Hugh Lewis in Southampton to discover how the international community is set up to respond to any future threats, and to find out who will decide what action to take and the possible consequences it may have. But the skies and the asteroids in it aren’t just a scary threat to humanity; when we stop and look up, there are some beautiful sights to be seen, and Pete Lawrence is on hand to tell us what to look out for in the coming months. Join us for an exciting episode that looks beyond the headlines, to see what efforts were made to protect us from an asteroid that could have wiped out a city the size of Greater London – and beyond.
Links:
The Sky at Night

Strongest hints yet of biological activity outside the solar system / New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI - publication
2025-04-17
Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious.
Using data from the James Webb Space Telescope (JWST), the astronomers, led by the University of Cambridge, have detected the chemical fingerprints of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS), in the atmosphere of the exoplanet K2-18b, which orbits its star in the habitable zone. On Earth, DMS and DMDS are only produced by life, primarily microbial life such as marine phytoplankton. While an unknown chemical process may be the source of these molecules in K2-18b’s atmosphere, the results are the strongest evidence yet that life may exist on a planet outside our solar system. The observations have reached the ‘three-sigma’ level of statistical significance – meaning there is a 0.3% probability that they occurred by chance. To reach the accepted classification for scientific discovery, the observations would have to cross the five-sigma threshold, meaning there would be below a 0.00006% probability they occurred by chance. The researchers say between 16 and 24 hours of follow-up observation time with JWST may help them reach the all-important five-sigma significance. Their results are reported in The Astrophysical Journal Letters. Earlier observations of K2-18b — which is 8.6 times as massive and 2.6 times as large as Earth, and lies 124 light years away in the constellation of Leo — identified methane and carbon dioxide in its atmosphere. This was the first time that carbon-based molecules were discovered in the atmosphere of an exoplanet in the habitable zone.
Those results were consistent with predictions for a ‘Hycean’ planet: a habitable ocean-covered world underneath a hydrogen-rich atmosphere. However, another, weaker signal hinted at the possibility of something else happening on K2-18b. To determine the chemical composition of the atmospheres of faraway planets, astronomers analyse the light from its parent star as the planet transits, or passes in front of the star as seen from the Earth. As K2-18b transits, JWST can detect a drop in stellar brightness, and a tiny fraction of starlight passes through the planet’s atmosphere before reaching Earth. The absorption of some of the starlight in the planet’s atmosphere leaves imprints in the stellar spectrum that astronomers can piece together to determine the constituent gases of the exoplanet’s atmosphere. The earlier, tentative, inference of DMS was made using JWST’s NIRISS (Near-Infrared Imager and Slitless Spectrograph) and NIRSpec (Near-Infrared Spectrograph) instruments, which together cover the near-infrared (0.8-5 micron) range of wavelengths. The new, independent observation used JWST’s MIRI (Mid-Infrared Instrument) in the mid-infrared (6-12 micron) range. DMS and DMDS are molecules from the same chemical family, and both are predicted to be biosignatures.
Both molecules have overlapping spectral features in the observed wavelength range, although further observations will help differentiate between the two molecules. However, the concentrations of DMS and DMDS in K2-18b’s atmosphere are very different than on Earth, where they are generally below one part per billion by volume. On K2-18b, they are estimated to be thousands of times stronger – over ten parts per million. Madhusudhan says that while the results are exciting, it’s vital to obtain more data before claiming that life has been found on another world. He says that while he is cautiously optimistic, there could be previously unknown chemical processes at work on K2-18b that may account for the observations. Working with colleagues, he is hoping to conduct further theoretical and experimental work to determine whether DMS and DMDS can be produced non-biologically at the level currently inferred. While he is not yet claiming a definitive discovery, Madhusudhan says that with powerful tools like JWST and future planned telescopes, humanity is taking new steps toward answering that most essential of questions: are we alone? The James Webb Space Telescope is a collaboration between NASA, ESA and the Canadian Space Agency (CSA). The research is supported by a UK Research and Innovation (UKRI) Frontier Research Grant.
Links:
Strongest hints yet of biological activity outside the solar system
Wetenschappers vinden ‘sterkste tekenen tot nu toe’ van mogelijk buitenaards leven
Er is geen Planet K2-18B! bescherm het buitenaardse leven!

Babelsberger Sternennächte – Solar Orbiter – Röntgenblick auf die Sonne / Das Röntgenteleskop STIX | Dr. Iris Traulsen (TV webcast)
2025-04-17 20:00 - 21:00
Die Leibniz-Instituts für Astrophysik Potsdam (AIP) Babelsberger Sternennächte finden online statt, in der Regel gibt es immer am 3. Donnerstag im Monat einen neuen Vortrag einer Wissenschaftlerin oder eines Wissenschaftlers des AIP, der ab 20 Uhr auf dem YouTube-Kanal von Urknall, Weltall und das Leben ausgestrahlt wird.
Röntgenblick auf die Sonne:
In diesem Vortrag geht es um wissenschaftliche Ergebnisse, die u.a. mit dem Röntgenteleskop STIX an Bord des Solar Orbiter gewonnen wurden. Die ESA-Raumsonde Solar Orbiter kreist seit 2020 um die Sonne und untersucht sie mittels zehn verschiedener Instrumente an Bord. STIX beobachtet die heißesten Regionen und energiereichsten Prozesse in Sonneneruptionen. Über die letzten Jahre hinweg ist die Sonnenaktivität stetig angestiegen, so dass Forschende bereits über 70,000 dieser Strahlungsausbrüche beobachten konnten. Ein Schwerpunkt der Forschung liegt auf der Kombination von STIX mit anderen Instrumenten. So haben die Wissenschaftlerinnen und Wissenschaftler z.B. die ersten 3D-Bilder von Sonneneruptionen im Röntgenbereich erzeugt. Mit STIX und anderen Instrumenten auf Solar Orbiter untersuchen sie außerdem das Material, das von der Sonne weggeschleudert wird, insbesondere energiereiche Teilchen und Plasmawolken, und welche Konsequenzen daraus für die Erde und das Weltraumwetter folgen.
Das Röntgenteleskop STIX:
Hier können Interessierte hinter die technischen Kulissen des Röntgenteleskops STIX schauen. Dr. Alexander Warmuth geht in diesem Vortrag auf verschiedene Fragen ein: Wie funktioniert eigentlich so ein Röntgenteleskop? Wie erzeugt es Röntgenbilder der Sonne, obwohl die Strahlung so energiereich ist, dass in dem Teleskop weder Linsen noch Spiegel verwendet werden können? Was sind die Anforderungen an ein Instrument, welches sich stärker der Sonne annähert als der sonnennächste Planet Merkur?
Links:
Babelsberger Sternennächte
Babelsberger Sternennächte – playlist

Meteorenzwerm α-Virginiden in april 2025
2025-04-18 05:00 - 17:00
De meteorenzwerm α-Virginiden bereikt op vrijdag 18 april 2025, rond 05:00, zijn maximum.
Wanneer de radiant in het zenit zou staan, zouden er van deze zwerm naar verwachting gemiddeld zo’n 5 meteoren per uur vallen. Rond 01:00 staat de radiant van de zwerm in het hoogste punt (op 36°) aan de hemel. Er is dan bij ons ieder uur slechts een enkele meteoor van deze zwerm zichtbaar. Samen met meteoren van andere zwermen, en sporadische meteoren, zijn er bij donkere, heldere hemel in totaal circa 3–8 meteoren per uur zichtbaar. Op een goed donkere plek zijn ongeveer drie keer zoveel meteoren zichtbaar als in een grote stad. De Maan komt om 02:19 op, is voor ongeveer 80% verlicht en kan flink storen; de zwakkere meteoren zullen hierdoor dit jaar niet zichtbaar zijn. Waarnemen voor de opkomst van de Maan kan dus gunstig zijn. Rond 06:00 gaat het schemeren en om 06:36 komt de Zon op. Over het algemeen zijn de de meteoren van een zwerm niet alleen op de dag van het maximum zichtbaar. Zo is gedurende circa 9 dagen rondom het maximum ruim de helft van het maximale aantal meteoren (1 per uur) van de α-Virginiden te zien. Tot 7 dagen voor en na het maximum zijn nog meteoren van deze zwerm te herkennen. Er zijn dus nog meer kansen, voor het geval het in de nacht van het maximum niet helder is. Iedere dag verder weg van het maximum zijn er echter wel ongeveer 20% minder meteoren per uur te zien. De typische snelheden van de meteoren in deze zwerm zijn met circa 17 km/s (ongeveer 60.120 km/uur) relatief laag. Er is geen speciale apparatuur nodig om meteoren waar te kunnen nemen.
Links:
Meteorenzwerm α-Virginiden in april 2025
