Mark Thompson, Author at Universe Today

November 23, 2023November 23, 2023 by Mark Thompson

There Were Glaciers… on Mercury?

A view of Mercury’s north polar chaotic terrain (Borealis Chaos) and the Raditladi and Eminescu craters where evidence of possible glaciers has been identified. Red areas identified regions of potential salt glaciers — A view of Mercury’s north polar chaotic terrain (Borealis Chaos) and the Raditladi and Eminescu craters where evidence of possible glaciers has been identified (Credit: NASA)

I have lost count of how many times I have given public lectures and explained the temperature differences between Mercury and Venus. How Mercury, surprisingly isn’t the hottest planet in the Solar System and how that badge goes to Venus, thick atmosphere blah blah blah. Mercury and its complex surface geology does of course get a good chunk of time but a recent paper has rather caught my attention and turned what I thought I knew about Mercury on its head! In short, a team of scientists have announced evidence for salt glaciers on Mercury!

November 22, 2023November 22, 2023 by Mark Thompson

A Galaxy Seen When the Universe was Only 332 Million Years Old

The second- and fourth-most distant galaxies ever seen (UNCOVER z-13 and UNCOVER z-12) have been confirmed using the James Webb Space Telescope’s Near-Infrared Camera (NIRCam). The galaxies are located in Pandora’s Cluster (Abell 2744), show here as near-infrared wavelengths of light that have been translated to visible-light colors. The scale of the main cluster image is labelled in arcseconds, which is a measure of angular distance in the sky. The circles on the black-and-white images, showing the galaxies in the NIRCam-F277W filter band onboard JWST, indicate an aperture size of 0.32 arcsec. — JWST Deep Field showing the location of the second and fourth most distant galaxies in the Universe (Credit: NASA with Composition: Dani Zemba/Penn State)

It’s wonderful to watch the fascination on people’s faces when you explain to them that studying distant objects in the Universe means looking back in time! Reach out to the furthest corners of the Cosmos and you can see objects so far away that the light left them long before our Solar System even existed. With the commissioning of the JWST the race was on to push the boundaries even further and hunt down the most distant galaxy in the Universe and maybe even the first galaxies to ever have formed.

November 21, 2023November 21, 2023 by Mark Thompson

In the Shadow of Saturn’s Rings

This image is a composite of observations made of Saturn in early 2018 in the optical and of the auroras on Saturn’s north pole region, made in 2017. Image from NASA/ESA Hubble Space Telescope — Composite image of Saturm from HST (Credit NASA/ESA)

I can remember it very well, although not actually sure when it was, back around 1995/1996 I think. I was, like most other keen stargazers very familiar with the sight of Saturn with rings and all. Indeed the view of Saturn with its rings was one of the first things I had ever seen through a telescope and it inspired me into a lifetime passion of exploring the night sky. Every 15 years though, the Earth passes through the plane of the rings and from Earth they seem to vanish. Now, an astronomer has used data taken during such ring plane crossings from the Cassini spacecraft to measure the transparency of the rings.

November 21, 2023November 21, 2023 by Mark Thompson

JWST Peers into the Atmosphere of a Puffy, Fluffy Planet!

The exoplanet WASP-107b is a gas giant, orbiting a highly active K-type main sequence star. The star is about 200 light-years from Earth. — Artist impression of WASP107B as it transits its host star

Exoplanets are definitely a bit of a hot topic at the moment. Throw in a sprinkling of the James Webb Space Telescope (JWST) and you have the recipe for magic! I still cannot believe that we have discovered, yes actually discovered 5,539 exoplanets and there more being confirmed every day!The first exoplanet was discovered in 1992 and now over five and a half THOUSAND planets around other star systems are known! A team of astronomers have been exploring one in particular, the enigmatic WASP-107b using JWST and have made some incredible discoveries about its atmosphere.

November 19, 2023November 19, 2023 by Mark Thompson

A New Technique Has Dramatically Improved ALMA’s Resolution

Image showing two of the receivers of the ALMA array in the Atacama Desert. — Two of the Atacama Large Millimeter/submillimeter Array (ALMA) 12-metre antennas (Credit : Iztok Bon?ina/ESO)

To those familiar with optical telescopes, the idea of doing something to achieve higher resolution with their telescope may seem alien, if not, then practically impossible. A telescopes resolution is determined by among other things, its aperture – diameter of the thing that collects light (or electromagnetic radiation) and of course you can’t easily change that. Enter the team at ALMA, the Atacama Large Millimeter Array who have become the first to use the Band 10 receiver and extreme separation of the receivers to boosting its resolution so they can see detail equivalent of detecting a 10 meter long bus on the Moon!

November 16, 2023November 16, 2023 by Mark Thompson

An Asteroid Will Occult Betelgeuse on December 12th

Image of Betelgeuse and graphic showing its location — Image of Betelgeuse (Credit NASA/ESA)

I cannot for the life of me remember when it was or what it was but a fair few years ago I remember positioning a telescope to observe an asteroid as it silently and perhaps slightly eerily drifted between us and the Moon. I say eerily as this asteroid had the ability to cause widespread damage had it hit but of course we knew it posed no threat. I remember at the time thinking it was mind blowing that even today, we still use mathematics with roots (pardon the pun) centuries old to calculate the position of objects in our Solar System. We get to see evidence of this again on 12th December when something rare happens!

November 15, 2023November 15, 2023 by Mark Thompson

Need to Map an Iceberg in a Hundredth of a Second? Ask a Computer

Image of an iceberg on the Arctic Ocean — An Iceberg in the Arctic Ocean

Satellites really are quite a wonder. They can help forecast the weather, track climate change and help you navigate around the world. There are even satellites that can not only track icebergs but can map the Antarctic in the merest blink of an eye. In fact, faster than that since a typical blink takes about 0.2 seconds but the Sentinel-1 satellites can map icebergs in just 0.01 seconds, that’s 20 times for every blink of an eye!

November 14, 2023November 14, 2023 by Mark Thompson

When Stars Consume Their Partners, We Could Detect a Blast of Neutrinos

Three thousand light-years away, the Cat's Eye Nebula, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the nebula to be one of the most complex planetary nebulae known.The features seen in the Cat's Eye are so complex that astronomers suspect the central object may actually be a binary star system. — The Cat's Eye Nebula (NGC6543) is thought to be caused by a binary star system. Credit - NASA/HST

You might be familiar with the bizarre ritual of the female praying mantis which, I’m told, bites off the head and eats other body parts of the poor male they just mated with. It seems consuming partners is not unheard of. It’s even seen in the lives of stars where binary stars orbit one another closely and one star ultimately consumes the other. If the victim is a neutron star a burst of neutrinos can be generated and a new study reveals they might just be detectable on Earth.

November 13, 2023November 13, 2023 by Mark Thompson

Starship Could Be Ready to Launch on Friday

SpaceX Starship's Superheavy Booster, serial no. B7, being tested on the orbital launch pad at Starbase, Boca Chica, Texas in February 2023. — SpaceX Starship's Superheavy Booster at Starbase, Boca Chica, Texas (Credit : Mobilus In Mobili)

Space exploration should never be run of the mill nor something that finds itself on the back pages of the newspaper. Captain James T. Kirk was right that space really is the final frontier and making it more accessible is one of the driving forces behind SpaceX. Their mission to seek out new life and new civilisations, wait that’s wrong – that’s Starfleet. The SpaceX mission ‘to revolutionise space technology, with the ultimate goal of enabling people to live on other planets is at the forefront of the development of the enormous Starship which may make another launch attempt as soon as this Friday 17th November.

November 12, 2023November 12, 2023 by Mark Thompson

Mystery Solved. How We Get Ultra-Compact Dwarf Galaxies

This NASA/ESA Hubble Space Telescope image shows the dwarf galaxy M60-UDC1. Lying about 50 million light-years away, M60-UCD1 is a tiny galaxy with a diameter of 300 light-years — just 1/500th of the diameter of the Milky Way! Despite its size it is pretty crowded, containing some 140 million stars. The dwarf galaxy may actually be the stripped remnant of a larger galaxy that was torn apart during a close encounter with its neighbour, a massive galaxy called Messier 60. Circumstantial evidence for this comes from the recent discovery of a monster black hole, which is not visible in this image, at the centre of the dwarf. The black hole makes up 15 percent of the mass of the entire galaxy, making it much too big to have formed inside a dwarf galaxy. — Ultra Compact Dwarf Galaxy M60-UCD1 (Credit NASA/ESA and A.Seth)

I have been fascinated by galaxies for most of my adult life. I find it amazing that, just as we can ascertain the lifecycle of a tree by closely studying the trees in a forest, it is possible to study a sample of galaxies and understand galactic evolution. A team of astronomers using the Gemini North Telescope have recently solved a long standing galactic mystery, namely how we get ultra-compact dwarf galaxies (UCDs to use their catchy acronym).