Mark Thompson, Author at Universe Today

July 27, 2024July 27, 2024 by Mark Thompson

Giant Collision Decouples Dark Matter from Regular Matter

This artist's concept shows what happened when two massive clusters of galaxies, collectively known as MACS J0018.5, collided: The dark matter in the galaxy clusters (blue) sailed ahead of the associated clouds of hot gas, or normal matter (orange). Both dark matter and normal matter feel the pull of gravity, but only the normal matter experiences additional effects like shocks and turbulence that slow it down during collisions. Credit: W.M. Keck Observatory/Adam Makarenko

Dark matter is a mysterious and captivating subject. It’s a strange concept and we don’t really have a handle on what it actually is. One of the strongest pieces of evidence that dark matter is a particle comes from cosmic collisions. These collisions chiefly occur when clusters of galaxies interact such as the famous Bullet Cluster. Gravitational lensing reveals how the dark matter component couples from gas and dust in the cluster but now, astronomers have found another galaxy cluster collision but it is different, showing the collision from a new angle.

July 27, 2024July 27, 2024 by Mark Thompson

Kepler Sketched the Sun in 1607. Astronomers Pinpointed the Solar Cycle

The earliest datable sunspot drawings based on Johannes Kepler's solar observations with camera obscura in May 1607.

Johannes Kepler is probably most well known for developing the laws of planetary motion. He was also a keen solar observer and in 1607 made some wonderful observations of our nearest star using a camera obscura. His drawings were wonderfully precise and enabled astronomers to pinpoint where the Sun was in its 11-year cycle. Having taken into account Kepler’s location and the location of sunspots, a team of researchers have identified the Sun was nearing the end of solar cycle-13.

July 27, 2024July 27, 2024 by Mark Thompson

Update your Desktop Wallpaper with 25 New Images from Chandra

This collection of images was released to commemorate the 25th anniversary of Chandra. Image credit: NASA / CXC / SAO.

It’s not always possible to observe the night sky from the surface of the Earth. The blocking effects of the atmosphere mean we sometimes need to put telescopes out into space. The Chandra X-Ray Observatory is one such telescopes and it has just completed its 25th year of observations. To celebrate, NASA have just released 25 never-before-seen images of various celestial objects in x-rays. The collection includes images showing the region around black holes, giant clouds of hot gas and extreme magnetic fields. Sadly though, NASA is planning on shutting down the mission to save budget so best to enjoy the images while you can.

July 25, 2024July 25, 2024 by Mark Thompson

Now Uranus’ Moon Ariel Might Have an Ocean too

An image mosaic of Uranus’ moon Ariel, taken by the narrow-angle camera on Voyager 2 on Jan. 24, 1986. Credit: NASA/Jet Propulsion Laboratory

Venus is known for being really quite inhospitable with high surface temperatures and Mars is known for its rusty red horizons. Even the moons of some of the outer planets have fascinating environments with Europa and Enceladus boasting underground oceans. Recent observations from the James Webb Space Telescope show that Ariel, a moon of Uranus, is also a strong candidate for a sub surface ocean. How has this conclusion been reached? Well JWST has detected carbon dioxide ice on the surface on the trailing edge of features trailing away from the orbital direction. The possible cause, an underground ocean!

July 25, 2024July 25, 2024 by Mark Thompson

Why is JWST Having So Much Trouble with the TRAPPIST-1 System?

A new step-by-step roadmap describes how to improve the efficiency of data gathering with the JWST to benefit the astronomy community at large. “Our hope now is that a large-scale community effort guided by the roadmap can be initiated to yield deliverables at a timely pace,” says MIT Associate Professor Julien de Wit. Credits:Image components courtesy of NASA/JPL-Caltech.

When the James Webb Space Telescope was launched it came with a fanfare expecting amazing things, much like the Hubble Space Telescope. One of JWST’s most anticipated target was TRAPPIST-1. This inconspicuous star is host to seven Earth-sized planets, with at least three in the habitable zone. The two inner planets are airless worlds but so far there has been no word of the third planet, the first in the habitable zone. The question is why and what makes it so tricky to observe?

July 24, 2024July 24, 2024 by Mark Thompson

Astronauts Can Now Watch 4K Streaming Video on the Station

A graphic representation of a laser communications relay between the International Space Station, the Laser Communications Relay Demonstration spacecraft, and the Earth. Credit: NASA/Dave Ryan

We take high definition streaming for granted in many parts of the world. Even now, as I type this article, I have the Martian streaming in high definition but until now astronauts on board the Space Station have had to accept low definition streaming. A team of researchers at NASA have developed and used a new system using an aircraft as a relay. A laser terminal was installed on a research aircraft and data was sent to a ground station. The signals were sent around the Earth and beamed to a relay satellite which then sent the signal on to the Space Station. What the astronauts will actually use it for is less likely to be streaming HD movies but will certainly be able to take advantage of the high bandwidth for science data and communications.

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.