Scott Alan Johnston, Author at Universe Today

May 12, 2024May 12, 2024 by Scott Alan Johnston

Do Clashing Galaxies Create Odd Radio Circles?

This multiwavelength image of the Cloverleaf ORC (odd radio circle) combines visible light observations from the DESI (Dark Energy Spectroscopic Instrument) Legacy Survey in white and yellow, X-rays from XMM-Newton in blue, and radio from ASKAP (the Australian Square Kilometer Array Pathfinder) in red. X. Zhang and M. Kluge (MPE), B. Koribalski (CSIRO)

Within the last five years, astronomers have discovered a new type of astronomical phenomenon that exists on vast scales – larger than whole galaxies. They’re called ORCs (odd radio circles), and they look like giant rings of radio waves expanding outwards like a shockwave. Until now, ORCs had never been observed in any wavelength other than radio, but according to a new paper released on April 30 2024, astronomers have captured X-rays associated with an ORC for the first time.

April 18, 2024April 18, 2024 by Scott Alan Johnston

The Mystery of Cosmic Rays Deepens

The Fred Lawrence Whipple Observatory’s 48-inch telescope captured this visible-light image of the Pinwheel galaxy (Messier 101) in June 2023. The location of supernova 2023ixf is circled. The observatory, located on Mount Hopkins in Arizona, is operated by the Center for Astrophysics | Harvard & Smithsonian. Hiramatsu et al. 2023/Sebastian Gomez (STScI)

Cosmic rays are high-energy particles accelerated to extreme velocities approaching the speed of light. It takes an extremely powerful event to send these bits of matter blazing through the Universe. Astronomers theorize that cosmic rays are ejected by supernova explosions that mark the death of supergiant stars. But recent data collected by the Fermi Gamma-ray space telescope casts doubt on this production method for cosmic rays, and has astronomers digging for an explanation.

April 4, 2024April 4, 2024 by Scott Alan Johnston

The Moon Will Get its Own Time Zone

Gravitational Wave science holds great potential that scientists are eager to develop. Is a gravitational wave observatory on the Moon the way forward? NASA/Goddard/LRO.

White House officials have directed NASA to begin work on establishing a standard time for the Moon, according to a report from Reuters this week. Coordinated Lunar Time (LTC) is intended to help ensure synchronization between the various lunar activities planned under the Artemis program.

April 3, 2024April 3, 2024 by Scott Alan Johnston

What's the Earliest the Moon Could Have Formed?

Artist's impression of the giant impact that shaped the Earth and created the Moon. Credit: NASA/JPL-Caltech.

Astronomers are pretty sure they know where the Moon came from. In the early Solar System, a Mars-sized object dubbed Theia smashed into Earth. This cataclysmic collision knocked a huge mass of material into orbit, which coalesced and cooled into the Moon. But establishing exactly when this occurred is a difficult task. At the 55th annual Lunar and Planetary Science Conference (LPSC 55) last month in The Woodlands, Texas, researchers proposed a new timeline of events that moves the giant impact earlier than previous predictions, at just 50 million years after the formation of the Solar System.

March 29, 2024March 29, 2024 by Scott Alan Johnston

Astronomers Catch a Supernova Explode Almost in Realtime

A composite image taken with the Liverpool Telescope showing the location of SN 2023ixf, a red supergiant supernova (the most blue object in the rectangle) that occurred 22 million light-years from Earth in the Pinwheel Galaxy. Credit: E. Zimmerman et al., Weizmann Institute of Science/Liverpool Telescope.

Catching a supernova in action is tricky business. There is no way to predict them, and they don’t occur very often. Within the Milky Way they only occur about once a century, and the last one was observed in 1604.

March 23, 2024March 23, 2024 by Scott Alan Johnston

Red Giants Offer a New Way to Measure Distance in the Universe

The Large Magellanic cloud. Credit: CTIO/NOIRLab/NSF/AURA/SMASH/D. Nidever (Montana State University) Image processing: Travis Rector (University of Alaska Anchorage), Mahdi Zamani & Davide de Martin.

For nearly three decades now, it’s been clear that the expansion of the Universe is speeding up. Some unknown quantity, dramatically dubbed ‘dark energy’, is pushing the Universe apart. But the rate at which the Universe’s expansion is increasing – called the Hubble Constant – hasn’t yet been nailed down to a single number.

Not for lack of trying.

March 10, 2024March 10, 2024 by Scott Alan Johnston

Ariane 6 is Coming Together

Part of the first Ariane 6 rocket inside the Vehicle Assembly Building, Kourou, French Guiana earlier in 2024. Credit: ESA/CNES/Arianespace/Arianegroup.

The European Space Agency (ESA)’s next generation heavy lift rocket is just months away from its first flight, and its major components are now being assembled for launch at the Vehicle Assembly Building in Kourou, French Guiana.

February 22, 2024February 22, 2024 by Scott Alan Johnston

If Hycean Worlds Really Exist, What are Their Oceans Like?

Artist's impression of possible hycean world K2-18 b. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

Astronomers have been on the hunt for a new kind of exoplanet in recent years – one especially suited for habitability. They’re called hycean worlds, and they’re characterized by vast liquid water oceans and thick hydrogen-rich atmospheres. The name was coined in 2021 by Cambridge astronomer Nikku Madhusudhan, whose team got a close-up look at one possible hycean world, K2-18b, using the James Webb Space Telescope in 2023. In a newly accepted paper this January, Madhusudhan and coauthor Frances Rigby examined what the internal structure of hycean planets might look like, and what that means for the possibility of finding life within.

February 17, 2024February 17, 2024 by Scott Alan Johnston

China's Chang'e-8 Mission Will Try to Make Bricks on the Moon

Artist's impression of Chang'e-8. Credit: CNSA.

The China National Space Administration (CNSA) has put out a call for international and industry partners to contribute science payloads to its Chang’e-8 lunar lander, set for launch to the Moon in 2028. The mission, which will involve a lander, a rover, and a utility robot, will be China’s first attempt at in-situ resource utilization on the Moon, using lunar regolith to produce brick-like building materials.