Mark Thompson, Author at Universe Today

August 5, 2024August 5, 2024 by Mark Thompson

Starlink Direct-to-Cell Satellites are Coming. What Will Be Their Impact on Astronomy?

Mention the name Starlink among the astronomy community and you will often be greeted with a shudder. There are now thousands of Starlink satellites orbiting Earth providing internet connectivity to every corner of the Earth. Many believe they are making astronomy difficult but now, SpaceX is launching another service; ‘direct-to-cell’ technology that will allow mobile phones to use satellites to send text messages as early as this year. Voice and data services are likely to follow on quickly next year. With smaller antennae at a lower altitude what is their impact on astronomy?

August 5, 2024August 5, 2024 by Mark Thompson

Astronomers See Planets Forming Around Binary Stars

Artist's illustration of binary star planet formation. Credit: S. Dagnello, NSF/AUI/NRAO

Over 5,000 exoplanets have been discovered around distant star systems. Protoplanetary disks have been discovered too and it’s these, out of which all planetary systems form. Such disks have recently been found in two binary star systems. The stellar components in one have a separation of 14 astronomical units (the average distance between the Earth and Sun is one astronomical unit) and the other system has a separation of 22 astronomical units. Studying systems like these allow us to see how the stars of a binary system interact and how they can distort protoplanetary disks.

July 31, 2024July 31, 2024 by Mark Thompson

This Binary Asteroid is Messed Up. It’s Probably Earth’s Fault

Radar images of 1991 VH and its satellite by Arecibo Observatory in 2008

Space is big, really big! Finding new asteroids which are usually dark against the inky blackness of space is harder than looking for a needle in a cosmic haystack. Back in 1991 an astronomer discovered a kilometre wide asteroid which was subsequently found to have a smaller moon half its size. It was given the snappy name of 1991 VH which , after follow up observations was revealed to have a tumbling, chaotic rotation. This was the first binary asteroid that has been seen to exhibit this behaviour. A paper just published suggests that a close encounter with Earth as recently as 12,000 years ago could have started its tumbling motion.

July 31, 2024July 31, 2024 by Mark Thompson

Starliner Successfully Fires its Thrusters, Preparing to Return to Earth

Boeing’s Starliner crew capsule docked to the Harmony module’s forward port at the International Space Station on July 6, 2024. Photo credit: NASA

Being trapped in space sounds like the stuff of nightmares. Astronauts on board the International Space Station have on occasion, had their return delayed by weather or equipment malfunction. We find ourselves again, watching and waiting as two astronauts; Juni Williams and Butch Wilmore have been stuck for months instead of their week long mission. The delays came as the Starliner system required fixes to be implemented. NASA successfully fired up 27 of its 28 thrusters in a hot-firing test and now, ground teams are preparing finally, to bring them home.

July 30, 2024July 30, 2024 by Mark Thompson

A Surprising Source of Oxygen in the Deep Sea

Manganese nodules from the seafloor are often rich in metals like manganese, iron, nickel, copper, and cobalt.

I have always found Mariana’s Trench fascinating, it’s like an alien world right on our doorstep. Any visitor to the oceans or seas of our planet will hopefully get to see fish flitting around and whilst they can survive in this alien underwater world they still need oxygen to survive. Breathing in oxygen is a familiar experience to us, we inflate our lungs and suck air into them to keep us topped up with life giving oxygen. Fish are different, they get their oxygen as water flows over their gills. Water is full of oxygen which at the surface comes from the atmosphere or plants. But deep down, thousands of meters beneath the surface, it is not so easy. Now a team of scientists think that potato-sized chunks of metal called nodules act like natural batteries, interacting with the water and putting oxygen into the deep water of the ocean.

July 30, 2024July 30, 2024 by Mark Thompson

When Earth Danced with Polar Moons

The origins of the Moon have been the cause of many a scientific debate over the years but more recently we seem to have settled on a consensus. That a Mars-sized object crashed into Earth billions of years ago, with the debris coalescing into the Moon. The newly formed Moon drifted slowly away from Earth over the following eons but a new study suggests some surprising nuances to the accepted model.

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!