Universe Today

December 22, 2023December 22, 2023 by Paul M. Sutter

Holograms Might Save Physics

Observations made with ESO’s Very Large Telescope (VLT) have revealed for the first time that a star orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s theory of general relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton's theory of gravity. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole. This artist’s impression illustrates the precession of the star’s orbit, with the effect exaggerated for easier visualisation.

Even though the guts of General Relativity are obtusely mathematical, and for decades was relegated to math departments rather than proper physics, you get to experience the technological gift of relativity every time you navigate to your favorite restaurant. GPS, the global positioning system, consists of a network of orbiting satellites constantly beaming out precise timing data. Your phone compares those signals to figure out where you are on the Earth. But there is a difference in spacetime between the surface of the Earth and the orbit of the satellites. Without taking general relativity into account, your navigation would simply be incorrect, and you’d be late for dinner.

December 22, 2023December 22, 2023 by Scott Alan Johnston

Ouch. Canadarm2 Took a Direct Hit From a Micrometeorite

Canadarm with a micrometeorite impact: ESA/NASA-A.Mogensen.

Living in space comes with risks. For astronauts on the International Space Station (ISS), those risks occasionally make themselves intrusively apparent.

Earlier this month, European Space Agency astronaut Andreas Mogensen snapped a photo of the Canadarm2, in which damage from a micrometeorite impact is clearly visible.

December 22, 2023December 22, 2023 by Laurence Tognetti

Should We Send Humans to Titan?

Universe Today recently examined the potential for sending humans to Jupiter’s icy moon, Europa, and the planet Venus, both despite their respective harsh surface environments. While human missions to these exceptional worlds could be possible in the future, what about farther out in the solar system to a world with much less harsh surface conditions, although still inhospitable for human life? Here, we will investigate whether Saturn’s largest moon, Titan, could be a feasible location for sending humans sometime in the future. Titan lacks the searing temperatures and crushing pressures of Venus along with the harsh radiation experienced on Europa. So, should we send humans to Titan?

December 21, 2023December 22, 2023 by Carolyn Collins Petersen

Should We Be Preparing for First Contact?

First Contact. It’s a topic guaranteed to inspire a mix of emotions in people. It’s also one of the most fascinating SF scenarios we can imagine. What will people do when “they” appear? Or when we find evidence of life elsewhere in the Universe? For answers, one suggestion is to turn to a discipline called “exosociology”.

December 21, 2023December 21, 2023 by Laurence Tognetti

Dream Chaser is Getting Tested at NASA

After a journey spanning almost two decades, Sierra Nevada Corporation’s Dream Chaser reusable spaceplane, named Tenacity, is officially undergoing environmental testing at NASA’s Neil Armstrong Test Facility located at NASA’s Glenn Research Center in anticipation of its maiden flight to the International Space Station (ISS), currently scheduled for April 2024. The environmental testing consists of analyzing the spacecraft’s ability to withstand rigorous vibrations during launch and re-entry, along with the harsh environment of outer space, including extreme temperature changes and vacuum conditions. This testing comes after Sierra Space announced the completion of Tenacity at its facilities in Louisville, Colorado last month, along with the delivery of Sierra Space’s cargo module, Shooting Star, to the Neil Armstrong Test Facility that same month, as well.

December 21, 2023December 21, 2023 by Mark Thompson

ESA is Stockpiling Simulated Regolith for the Ultimate Lunar Playground.

Testing interplanetary landers means putting them in an environment as close to their destination as possible. Mars landers are often tested in the ‘Mars Yard’ at NASA’s Jet Propulsion Laboratory in South California and now, ESA are looking to build a similar test bed for the Moon. They are mining a mateiral in Greenland known as Anorthosite to create the largest lunar test bed yet.

December 21, 2023December 21, 2023 by Andy Tomaswick

Lost In Space? Just Use Relativity

One of the hardest things for many people to conceptualize when talking about how fast something is going is that they must ask, “Compared to what?” All motion only makes sense from a frame of reference, and many spacecraft traveling in the depths of the void lack any regular reference from which to understand how fast they’re going. There have been several different techniques to try to solve this problem, but one of the ones that have been in development the longest is StarNAV – a way to navigate in space using only the stars.

December 21, 2023December 21, 2023 by Evan Gough

Webb Sees a Supernova Go Off in a Gravitationally Lensed Galaxy – for the Second Time

NASA’s James Webb Space Telescope has spotted a multiply-imaged supernova in a distant galaxy designated MRG-M0138. Image Credit: NASA, ESA, CSA, STScI, Justin Pierel (STScI) and Andrew Newman (Carnegie Institution for Science).

Nature, in its infinite inventiveness, provides natural astronomical lenses that allow us to see objects beyond the normal reach of our telescopes. They’re called gravitational lenses, and a few years ago, the Hubble Space Telescope took advantage of one of them to spot a supernova explosion in a distant galaxy.

Now, the JWST has taken advantage of the same lens and found another supernova in the same galaxy.

December 21, 2023December 21, 2023 by Matt Williams

We Just had the Strongest Solar Flare in the Current Solar Cycle

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

On December 14th, at 12:02 PM Eastern (09:02 AM Pacific), the Sun unleashed a massive solar flare. According to the Space Weather Prediction Center, part of the National Oceanic Atmospheric Administration (NOAA), this was the strongest flare of Solar Cycle 25, which began in 2019 and will continue until 2030. What’s more, scientists at the SWPC estimate that this may be one of the most powerful solar flares recorded since 1755 when extensive recording of solar sunspot activity began.

December 21, 2023December 21, 2023 by Nancy Atkinson

It’s Time for Saturn’s “Spokes” to Return

This NASA Hubble Space Telescope photo of Saturn reveals the planet's cloud bands and a phenomenon called ring spokes. NASA, ESA, STScI, Amy Simon (NASA-GSFC)

Astronomers have been observing Saturn with the Hubble Space Telescope and several other spacecraft for decades and have noticed something unusual. During seasonal changes, transient spoke-like features appear in the rings. These dark, ghostly blobs orbit around the planet 2-3 times, and then disappear.

As Saturn is approaching its equinox, this is prime spoke activity time. Once again, Hubble has been called to gaze at Saturn, tracking the behavior of the spokes and hopefully giving astronomers more clues as to why they occur.