Mark Thompson, Author at Universe Today

July 23, 2024July 23, 2024 by Mark Thompson

New Horizons Measures the Background Light of the Universe

The locations of the NCOB, DCAL, SCAL, and IPD fields are shown on the IRIS full-sky 100 µm map in Galactic coordinates.

Think about background radiation and most people immediately think of the cosmic background radiation and stories of pigeon excrement during its discovery. That’s for another day though. Turns out that the universe has several background radiations, such as infrared and even gravitational wave backgrounds. NASA’s New Horizons is far enough out of the Solar System now that it’s in the perfect place to measure the cosmic optical background (COB). Most of this light comes from the stars in galaxies, but astronomers have always wondered if there are other sources of light filling our night sky. New Horizons has an answer. No!

July 23, 2024July 23, 2024 by Mark Thompson

Next Generation Event Horizon Telescope To Unlock Mysteries of Black Holes

Impact of scattering on the observed polarimetric spiral phase from one 345 GHz frame of the GRMHD simulation of Sgr A*

The prospect of actually resolving the event horizon of black holes feels like the stuff of science fiction yet it is a reality. Already the Event Horizon Telescope (EHT) has resolved the horizon of the black holes at the centre of the Milky Way and M87. A team of astronomers are now looking to the next generation of the EHT which will work at multiple frequencies with more telescopes than EHT. A new paper suggests it may even be possible to capture the ring where light goes into orbit around the black hole at the centre of the Milky Way.

July 23, 2024July 23, 2024 by Mark Thompson

The Entrance of a Lunar Lava Tube Mapped from Space

Craters are a familiar sight on the lunar surface and indeed on many of the rocky planets in the Solar System. There are other circular features that are picked up on images from orbiters but these pits are thought to be the collapsed roofs of lava tubes. A team of researchers have mapped one of these tubes using radar reflection and created the first 3D map of the tube’s entrance. Places like these could make ideal places to setup research stations, protected from the harsh environment of an alien world.

July 16, 2024July 16, 2024 by Mark Thompson

Pulsars are the Ideal Probes for Dark Matter

This artist's concept shows a pulsar, which is like a lighthouse, as its light appears in regular pulses as it rotates. Pulsars are dense remnants of exploded stars, and are part of a class of objects called neutron stars. http://photojournal.jpl.nasa.gov/catalog/PIA21085 Credit NASA/JPL-Caltech

Pulsars are the remnants of the explosion of massive stars at the end of their lives. The event is known as a supernova and as they rapidly spin they sweep a high energy beam across the cosmos much like a lighthouse. The alignment of some pulsar beams mean they sweep across Earth predictably and with precise regularity. They can be, and often are used as timing gauges but a team of astronomers have found subtle timing changes in some pulsars hinting at unseen mass between pulsars and telescopes—possibly dark matter entities.

July 16, 2024July 16, 2024 by Mark Thompson

Webb Maps the Weather on the Closest Brown Dwarfs to Earth

An artist’s impression of the nearest brown dwarf to Earth, WISE 1049AB, (pictured main), along with an impression of the stormy weather on a brown dwarf planet (inset). Credit ESO-I. Crossfield-N. Risinger

James Webb Space Telescope (JWST) has done it again. A team of astronomers have used it to map the weather on a pair of brown dwarf stars. Infrared light was analysed from the pair and its variation over time was measured. The team were able to generate a 3D picture of the weather and discovered gasses in the atmosphere like water vapour, methane and carbon dioxide. Swirling clouds of hot sand were also found with temperatures reaching as high as 950 C!

July 13, 2024July 13, 2024 by Mark Thompson

Galaxies Regulate their Own Growth so they Don’t Run Out of Star Forming Gas

A simulation of a galaxy’s ‘heart and lungs’ at work is pictured inset on an artist's impression of bi-polar jets of gas originating from a supermassive black hole at the centre of a galaxy. Credit ESA/Hubble, L. Calçada (ESO) / C Richards/MD Smith/University of Kent Licence type Attribution (CC BY 4.0)

Look at most spiral or barred spiral galaxies and you will see multiple regions where stars are forming. These star forming regions are comprised of mostly hydrogen gas with a few other elements for good measure. The first galaxies in the Universe had huge supplies of this star forming gas. Left unchecked they could have burned through the gas quickly, generating enormous amounts of star formation. Life fast though and die young for such an energetic burst of star formation would soon fizzle out leaving behind dead and dying stars. In some way it seems, galaxies seem to regulate their star formation thanks to supermassive black holes at their centre.

July 13, 2024July 13, 2024 by Mark Thompson

Mapping the Stars in a Dwarf Galaxy to Reveal its Dark Matter

Dark matter is curious stuff! As the name suggests, it’s dark making it notoriously difficult to study. Although it’s is invisible, it influences stars in a galaxy through gravity. Now, a team of astronomers have used the Hubble Space Telescope to chart the movements of stars within the Draco dwarf galaxy to detect the subtle gravitational pull of its surrounding dark matter halo. This 3D map required studying nearly two decades of archival data from the Draco galaxy. They found that dark matter piles up more in the centre, as predicted by cosmological models.

July 13, 2024July 13, 2024 by Mark Thompson

A Close Pulsar Measures 11.4 km Across

Animation of the millisecond pulsar PSR J0437-4715. On the left as seen from Earth. On the right as seen from the star's equatorial plane. (c) NASA/Sharon Morsink/Devarshi Choudhury et al.

When massive stars detonate as supernovae, they leave often behind a pulsar. These fast rotating stellar corpses have fascinated scientists since their discovery in 1967. One nearby pulsar turns 174 times a second and now, its size has been precisely measured. An instrument on board the International Space Station was used to measure x-ray pulses from the star. A supercomputer was then used to analyse its properties and found it was 1.4 times the mass of the Sun and measured only 11.4 km across!

July 9, 2024July 9, 2024 by Mark Thompson

Do Planets Have the Raw Ingredients for Life? The Answer is in their Stars

Finding planets that already have, or have the ingredients for intelligent life is a real challenge. It is exciting that new telescopes and spacecraft are in development that will start to identify candidate planets. Undertaking these observations will take significant amounts of telescope time so we need to find some way to prioritise which ones to look at first. A new paper has been published that suggests we can study the host stars first for the necessary raw elements giving a more efficient way to hunt for similar worlds to Earth.

July 9, 2024July 9, 2024 by Mark Thompson

The Rugged Desert Moss Best Equipped to Survive on Mars

For decades, we have seen Mars as a desolate landscape devoid of any signs of life. Attempt to identify ways of growing plants and food on the red planet have focussed on greenhouse like structures to enable plants to survive, that is, until now! A desert moss called ‘Syntrichia caninervis’ has been identified and it can grown in extreme environments like Antarctica and the Mojave Desert. A new study revealed the moss can survive Mars-like environments too including low temperatures, high levels of radiation and drought.