Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?

Obtaining accurate redshift measurements is a challenge, even with telescopes like Webb. Credit: NASA

One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its light has been traveling through space.

This is the purpose of the Cosmic Evolution Early Release Science Survey (CEERS), a collaborative research group that analyzes Webb data to learn more about galactic evolution. These galaxies are known as “high-redshift,” meaning that their light emissions are redshifted all the way into the infrared spectrum. Galaxies that existed ca. 13 billion years ago can only be observed in the near-infrared spectrum, which is now possible thanks to Webb’s Near-Infrared Camera (NIRCam). Even so, obtaining accurate redshift measurements from such distant galaxies is a very tricky, and requires advanced techniques.

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Psyche Gives Us Its First Images of Space

NASA's Psyche spacecraft has released its first images. The spacecraft is firing on all cylinders as it makes its way toward its target, the metal-rich asteroid with the same name. Image Credit: NASA

NASA’s Psyche mission began eight weeks ago when it launched from the Kennedy Space Center. While it won’t reach its objective, the metal-rich asteroid Psyche, until 2029, the spacecraft has already travelled 26 million km (16 million miles.) During that time, it’s already had its share of success as it ticks off items on its checklist of tests.

Now, we have our first images from Psyche. And while they don’t show us anything about its eventual target, they give us a behind-the-scenes look at how complex spacecraft prepare themselves as they cruise toward their destinations.

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What Would a Modern “Golden Record” Include?

Voyager's Golden Record. Credit: NASA/JPL
Voyager's Golden Record. Credit: NASA/JPL

Now that several decades have passed since the launch of Voyager 1 and Voyager 2 in 1977, we look back on that time with a hazy sense of history and what the event meant for humanity’s ongoing odyssey. While the Voyager spacecraft were sober scientific missions, they also carried with them a hint of the deeper yearnings that lie inside humanity’s heart: the Golden Records.

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Amateur Astronomers Found Planets Crashing Into Each Other

Artist impression of two colliding planets.

Astronomy is one of the sciences where amateurs make regular contributions. Over the years, members of the public have made exciting discoveries and meaningful contributions to the scientific process, either through direct observing, citizen science projects, or through combing through open data from the various space missions.

Recently, amateur astronomer Arttu Sainio saw a conversation on X (Twitter) where researchers were discussing the strange behavior of a dimming sun-like star. Intrigued, Arttu decided to look at the data on this star, called Asassn-21qj, on his own. Looking at archival data from NASA’s NEOWISE mission, Sainio was surprised to find that the star had dimmed before, with an unexpected brightening in infrared light two years before the optical dimming event. So, he joined the discussion on social media and shared his finding – which led to more amateurs joining the research, which lead to an incredible discovery.  

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15 Years of Data Reveal the Events Leading Up to Betelgeuse’s “Great Dimming”

Betelgeuse's dimming over the years. Image: ESO's Very Large Telescope
Betelgeuse's dimming over the years. Image: ESO's Very Large Telescope

Anyone who regularly watches the skies may well be familiar with the constellation Orion the hunter. It is one of the few constellations that actually looks like the thing it is supposed to look like rather than some abstract resemblance. One prominent star is Betelgeuse and back in 2020 it dimmed to a level lower than ever before in recorded history. A team of astronomers have been studying the event with some fascinating results.

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A Giant Stream of Stars is Flowing in Deep Space

The space between galaxies has long been considered a dead area. Single rogue stars may pop stars may pop up here or there, but the majority of this cosmic backward was considered empty by astronomers. But now, a paper from astronomers at various European and California institutions has found a trail of stars flowing between galaxies in a cluster.

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Scientists Found Evidence Of A Nearby Kilonova 3.5 Million Years Ago

Most of the times astronomers reported dramatic, cataclysmic events like neutron star mergers or the creation of a black hole; they are taking place light years away, typically in in another galaxy. While we can observe their destructive power through the light they emit, they have minimal impact on Earth. However, a relatively recent discovery of certain types of isotopes at the bottom of the ocean hints at one of these events happening fairly close to home. And it probably didn’t happen all that long ago.

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What Could a Next Generation Event Horizon Telescope Do?

Image of the M87 black hole by EHT and a CGI image photon ring. Image credit: EHT, Center for Astrophysics | Harvard & Smithsonian
Image of the M87 black hole by EHT and a CGI image photon ring. Image credit: EHT, Center for Astrophysics | Harvard & Smithsonian

Telescopes have come a long way in a little over four hundred years! It was 1608 that Dutch spectacle maker Hans Lippershey who was said to be working with a case of myopia and, in working with lenses discovered the magnifying powers if arranged in certain configurations. Now, centuries on and we have many different telescope designs and even telescopes in orbit but none are more incredible than the Event Horizon Telescope (EHT). Images las year revealed the supermassive black hole at the centre of our Galaxy and around M87 but now a team of astronomers have explored the potential of an even more powerful system the Next Generation EHT (ngEHT).

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