Universe Today

May 20, 2023May 20, 2023 by Brian Koberlein

Not All Type 1a Supernovae are Created Equally

Artist view of a binary system before a type Ia supernova. Credit: Adam Makarenko/W. M. Keck Observatory

Supernovae are brilliant explosions that can, for a time, outshine an entire galaxy. They come in two broad types: Type I and Type II. Type II supernovae are what are known as core-collapse supernovae. They occur when a massive dying star fuses ever heavier elements in its core until it runs out of energy options and its core collapses under its own weight, which triggers the explosion. Type I supernovae occur when…well, it’s complicated. But we’re learning more thanks to a new observation by radio astronomers.

May 20, 2023May 20, 2023 by Scott Alan Johnston

Artemis V is Going to the Moon With Blue Origin

NASA has announced a second lunar lander provider for its Artemis program, choosing Blue Origin’s National Team to deliver astronauts to the Moon’s south pole as early as 2029. Blue Origin’s lander will be part of the Artemis V mission. They join SpaceX, whose Starship is already slated to ferry astronauts to the lunar surface for Artemis III and IV.

May 20, 2023May 20, 2023 by Andy Tomaswick

ESO is Using a New System to Allocate Telescope Time. It’s Working Well

ESO's Very Large Telescope is composed of four Unit Telescopes (UTs) and four Auxiliary Telescopes (ATs). Seen here is one of the UTs firing four lasers which are crucial to the telescope's adaptive optics systems. To the right of the UT are two ATs, these smaller telescopes are moveable and work in tandem with the other telescopes to create a unique and powerful tool for observing the Universe.

Most astronomers know the struggle of getting time on the world’s most powerful telescopes. Even though this observing time might literally be the most important thing to their career prospects, there are always more studies than there is time available to perform them. Typically, each telescope system has a panel of experts that determine which proposals will get observational time and which won’t. However, the European Southern Observatory (ESO), based in Germany but with observational telescopes in Chile, decided to try a new proposal review method – peer review.

May 19, 2023May 19, 2023 by Matt Williams

New Climate Model Accurately Predicts Millions of Years of Ice Ages

Artist's impression of ice age Earth at glacial maximum. Credit: Wikipedia Commons/Ittiz

Earth experiences seasonal changes because of how its axis is tilted (23.43° relative to the Sun’s equator), causing one hemisphere to always be tilted towards the Sun (and the other away) for different parts of the year. However, because of gravitational interactions between the Earth, Sun, Moon, and other planets of the Solar System, Earth has experienced changes in its orientation (obliquity) over the course of eons. This has led to significant changes in Earth’s climate, particularly the recession and expansion of ice sheets due to significant variations in the distribution of sunlight and seasonal changes.

These warming and cooling periods are known as interglacial and glacial periods (“ice ages”). Another interesting change is how the glacial-interglacial cycle has become slower with time. While scientists have long suspected that astronomical forces are responsible, they have only recently been able to test this theory. In a recent study, a team of Japanese researchers reproduced the cycle of glacial periods during the early Pleistocene Epoch (1.6 to 1.2 million years ago) using an improved computer model that confirmed astronomical forces were responsible.

May 19, 2023May 21, 2023 by Matt Williams

An Astronomical First! A Radiation Belt Seen Outside the Solar System

Artist’s impression of an aurora and the surrounding radiation belt of the ultracool dwarf LSR J1835+3259. Credit: Chuck Carter/Melodie Kao/Heising-Simons Foundation)

In 1958, the first satellites launched by the United States (Explorer 1 and 3) detected a massive radiation belt around planet Earth. This confirmed something that many scientists suspected before the Space Age began: that energetic particles emanating from the Sun (solar wind) were captured and held around the planet by Earth’s magnetosphere. This region was named the Van Allen Belt in honor of University of Iowa professor James Van Allen who led the research effort. As robotic missions explored more of the Solar System, scientists discovered similar radiation belts around Jupiter, Saturn, Uranus, and Neptune.

Given the boom in extrasolar planet research, scientists have eagerly awaited the day when a Van Allen Belt would be discovered around an exoplanet. Thanks to a team of astronomers led by the University of California, Santa Cruz (UCSC) and the National Radio Astronomy Observatory (NRAO), that day may have arrived! Using the global High Sensitivity Array (HSA), the team obtained images of persistent, intense radio emissions from an ultracool dwarf star. These revealed the presence of a cloud of high-energy particles forming a massive radiation belt similar to what scientists have observed around Jupiter.

May 19, 2023May 19, 2023 by Brian Koberlein

Astronomers Want to Build the Next Generation Arecibo Telescope

The Arecibo Radio Telescope. Though it's decommissioned now, Arecibo Data may explain 1977's mysterious Wow! Signal. Image Credit: UCF

The Arecibo Telescope was an amazing tool for astronomers. Built in the early 1960s, it had a 1,000-foot-wide dish and was capable of both receiving and transmitting radio signals. It did radar mapping of near-Earth asteroids, Venus, and the Moon, discovered water at the polar regions of Mercury, searched for alien civilizations, and even send a radio message from Earth to a globular cluster 25,000 light years away. So when it collapsed in 2020, many astronomers wondered if it could be rebuilt.

May 19, 2023May 19, 2023 by Matt Williams

The Largest Explosion Ever Seen in the Universe

Artist impression of a black hole accretion. Credit: John A. Paice.

Throughout recorded history, humans have looked up at the night sky and witnessed the major astronomical events known as a “supernova.” The name, still used by astronomers, referred to the belief that these bursts of light in the “firmament” signaled the birth of a “new star.” With the birth of telescopes and modern astronomy, we have since learned that supernovae are what occur at the end of a star’s lifecycle. At this point, when a star has exhausted its hydrogen and helium fuel, it experiences gravitational collapse at its center.

This leads to a tremendous explosion that can be seen billions of light-years distant, releasing tremendous amounts of energy and blowing the star’s outer layers off. Thanks to an international team of astronomers led by the University of Southhampton, the most powerful cosmic explosion has been confirmed! The stellar explosion, AT2021lwx, took place about 8 billion light-years away in the constellation Vulpecula and was over ten times brighter than any supernova ever observed and 100 times brighter than all the stars in the Milky Way combined!

May 19, 2023May 13, 2023 by Paul M. Sutter

A Brief History of the Discovery of Cosmic Voids

An artist's impression of the cosmic web, the filamentary structure that fills the entire Universe. Credit: M. Weiss/CfA

At first the sum total of large, orderly structure in the Universe appeared to arrive in two categories. There were the clusters of galaxies – an unoriginal but descriptive name – each a dense ball with anywhere from a few dozen to a few hundred galaxies, all bound together by their mutual gravitational embrace. And then there were the field galaxies, lonely wanderers set apart and adrift from the clusters, not bound to anyone but themselves. That was it: the clusters of galaxies, the field galaxies, and the megaparsecs of emptiness that enveloped them all.

May 19, 2023May 20, 2023 by Andy Tomaswick

Building a Satellite out of Wood? Use Magnolia

Illustration of a wooden satellite. Credit: MidJourney

Typically when you think of a satellite, you think of a metal box with electronic components inside it. But that is simply because most satellites have been made that way throughout history. There is nothing against using other materials to build satellites. Now, a team of researchers from Japan has completed testing on another type of material that could eventually be used on an actual satellite – magnolia wood.

May 19, 2023May 19, 2023 by Laurence Tognetti

Mars Has a Thick Crust. Its Internal Heat Mainly Comes from Radioactivity

Elevation data of Mars featuring the lower elevations of the northern lowlands primarily in blue and the much higher elevations of the southern highlands primarily in orange and red. (Credit: MOLA Science Team)

How thick is the crust of Mars? This question is what a recent study published in Geophysical Research Letters attempted to answer as it reported on data from a magnitude 4.7 marsquake recorded in May 2022 by NASA’s InSight lander, which remains the largest quake ever recorded on another planetary body. As it turns out, this data helped provide estimates of Mars’ global crustal thickness, along with a unique discovery regarding the crust in the northern and southern hemispheres, and how the interior of Mars produces its heat.