Universe Today

February 8, 2021February 8, 2021 by Scott Alan Johnston

Jupiter’s Trojan Asteroids Offer Surprises Even Before NASA’s Lucy Mission has a Chance to Visit Them.

Artist’s Rendering of Lucy. Credit: Southwest Research Institute

A new study out this month suggests that Jupiter’s Trojan asteroids may be more peculiar than previously thought. The Trojan asteroids are rocky objects which orbit the Sun just ahead of and just behind the gas giant, in gravitational sweet spots known as Lagrange points. The swarm ahead of Jupiter, known as the L4 (Greek) group, is slightly larger than the L5 (Trojan) swarm behind, but until now, astronomers believed that there was otherwise little differentiation between the two swarms. The paper released this month appears to change that.

February 8, 2021February 23, 2023 by Matt Williams

What Are Extrasolar Planets?

An exoplanet about ten times Jupiter's mass located some 330 light years from Earth. X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS; Illustration: NASA/CXC/M.Weiss

For countless generations, human beings have looked out at the night sky and wondered if they were alone in the Universe. With the discovery of other planets in our Solar System, the true extent of the Milky Way galaxy, and other galaxies beyond our own, this question has only deepened and become more profound.

And whereas astronomers and scientists have long suspected that other star systems in our galaxy and the Universe had orbiting planets of their own, it has only been within the last few decades that any have been observed. Over time, the methods for detecting these “extrasolar planets” have improved, and the list of those whose existence has been confirmed has grown accordingly (over 4000 and counting!)

February 6, 2021February 6, 2021 by Andy Tomaswick

What’s Causing Those Landslides on Mars? Maybe Underground Salt and Melting Ice

Changes in Mar’s geography always attract significant scientific and even public attention. A hope for signs of liquid water (and therefore life) is likely one of the primary driving forces behind this interest. One particularly striking changing feature is the Recurring Slope Lineae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO). Now, scientists at the SETI Institute have a modified theory for where those RSLs might develop – a combination of water ice and salt just under the Martian surface.

February 6, 2021February 6, 2021 by Andy Tomaswick

Electrons Can Get Accelerated to Nearly the Speed of Light As They Interact With the Earth’s Magnetosphere

Electrons serve many purposes in physics. They are used by some particle accelerators and they underpin our modern world in the silicon chips that run the world’s computers. They’re also prevalent in space, where they can occasionally be seen floating around in a plasma in the magnetospheres of planets. Now, a team from the German Research Centre for Geosciences (GFZ) lead by Drs Hayley Allison and Yuri Shprits have discovered that those electrons present in the magnetosphere can be accelerated up to relativistic speeds, and that could potentially be hazardous to our increasing orbital infrastructure.

February 5, 2021February 5, 2021 by Evan Gough

Astronomers Can Predict When a Galaxy’s Star Formation Ends Based on the Shape and Size of its Disk

An ensemble of twenty-five disk galaxies. The view on the left shows light emitted in the H-alpha line from interstellar gas as a result of ongoing star-formation, while the panels on the right shows the optical light emitted by a mix of young (bluer) and old (redder) stars. Each galaxy can be seen rotated edge-on below its face-on view. Image Credit: TNG Collaboration

A galaxy’s main business is star formation. And when they’re young, like youth everywhere, they keep themselves busy with it. But galaxies age, evolve, and experience a slow-down in their rate of star formation. Eventually, galaxies cease forming new stars altogether, and astronomers call that quenching. They’ve been studying quenching for decades, yet much about it remains a mystery.

A new study based on the IllustrisTNG simulations has found a link between a galaxy’s quenching and its stellar size.

February 5, 2021February 5, 2021 by Andy Tomaswick

A New Radar Instrument Will Try To Fill the Void Left By Arecibo

Observational astronomy is dependent on its data, and therefore also dependent on the instruments that collect that data. So when one of those instruments fails it is a blow to the profession as a whole. The collapse of the Arecibo Telescope last year after it was damaged by Hurricane Maria in 2017 permanently deprived the radio astronomy world of one of its primary observational tools. Now a team at the National Radio Astronomy Observatory (NRAO) hopes to upgrade an existing telescope at the Green Bank Observatory in West Virginia to replace the failed Puerto Rican one and provide even more precise images of near Earth objects in the radio spectrum.

February 4, 2021February 5, 2021 by Andy Tomaswick

What Looked Like Phosphine On Venus Might Actually Just Be Sulfur Dioxide

There’s nothing like a good old fashioned science fight. When the discovery being challenged is one of the most public and intriguing of the last year, it’s bound to be even more interesting. A team of scientists, led by Andrew Lincowski and Victoria Meadows at the University of Washington (UW), and involving members from a variety of NASA labs and other universities, has challenged the discovery of phosphine in the atmosphere of Venus that was first announced last year. Their explanation is much simpler: it was most likely sulfur dioxide, one of the most abundant materials already known to be in Venus’ atmosphere.

February 4, 2021February 10, 2021 by Andy Tomaswick

Dark Energy Survey Finds Hundreds of New Gravitational Lenses

It’s relatively rare for a magical object from fantasy stories to have a analog in real life. A truly functional crystal ball (or palantir) would be useful for everything from military operations to checking up on grandma. While nothing exists to be able to observe the mundanities of everyday life, there is something equivalent for extraordinarily far away galaxies: gravitational lenses. Now a team led by Xiaosheng Huang from Lawrence Berkeley National Laboratory (LBNL) and several universities around the world have published a list of more than 1200 new gravitational lensing candidates.

February 4, 2021February 4, 2021 by Matt Williams

SLS Will be Tested Again in About 3 Weeks

The core stage for the first flight of NASA’s Space Launch System rocket is seen in the B-2 Test Stand during a scheduled eight minute duration hot fire test, Saturday, Jan. 16, 2021, at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credits: NASA/Robert Markowitz

In November of 2021, NASA will embark on a new era of space exploration as they make the inaugural launch of the Space Launch System (SLS). When it enters service, this booster will be the most powerful rocket since the Saturn V, which took the Apollo astronauts to the Moon. This is fitting since the SLS will be the rocket returning astronauts to the Moon by 2024 (as part of Project Artemis).

To get the SLS ready for its first launch, NASA has been running the Core Stage through a series of tests designed to test all the systems and components of the heavy-launch system – collectively known as a “Green Run.” The next step in this process will be a second Green Run Hot Fire Test, where all four RS-25 engines on the SLS Core Stage will fire at once to show they can operate as part of a single integrated system.

February 4, 2021February 1, 2021 by Paul M. Sutter

Astronomers are now Finding Planetary Disks Around the Smallest, Least Massive Stars

Astronomers have been watching planetary systems form around sun-like stars for decades. And now, new observations with the ALMA telescope reveal the same process playing out around the smallest, but most common, stars in galaxy.