Universe Today

July 20, 2020July 20, 2020 by Evan Gough

A Star had a Partial Supernova and Kicked Itself Into a High-Speed Journey Across the Milky Way

The material ejected by the supernova will initially expand very rapidly, but then gradually slow down, forming an intricate giant bubble of hot glowing gas. Eventually, the charred remains of the white dwarf that exploded will overtake these gaseous layers, and speed out onto its journey across the Galaxy. Credit: University of Warwick/Mark Garlick

Supernovae are some of the most powerful events in the Universe. They’re extremely energetic, luminous explosions that can light up the sky. Astrophysicists have a pretty good idea how they work, and they’ve organized supernovae into two broad categories: they’re the end state for massive stars that explode near the end of their lives, or they’re white dwarfs that draw gas from a companion which triggers runaway fusion.

Now there might be a third type.

July 20, 2020July 20, 2020 by Nancy Atkinson

Mount Everest, Seen from Space!

Mount Everest, as seen from the International Space Station. Picture taken by cosmonaut Oleg Artemyev.

One under-appreciated space asset is the photography skills of the Russian cosmonauts on board the International Space Station. They are extremely skillful photographers who don’t get the same recognition as their astronaut counterparts in their Earth observation skills. In particular, they have taken some stunning high-oblique shots of objects close to the horizon, with almost an 3-D effect.

July 20, 2020July 20, 2020 by Evan Gough

Astronomers Do the Math to Figure Out Exactly When Johannes Vermeer Painted this, More than 350 Years Ago

View of Delft is a famous oil painting by the Dutch Master Johannes Vermeer, painted ca. 1660–1661. Image Credit: By Johannes Vermeer - www.mauritshuis.nl : Home : Info : : Image, Public Domain, https://commons.wikimedia.org/w/index.php?curid=50398

Most of us will be forgotten only a generation or two after we pass. But some few of us will be remembered: great scientists, leaders, or generals, for example. But we can add history’s great artists to that list, and one in particular: Johannes Vermeer.

Vermeer was largely ignored during the two centures that followed his death, and died as other painters often did: penniless. But as more time has passed, the Dutch Baroque painter has grown in reputation, as historians increasingly recognize him as a master.

July 20, 2020July 20, 2020 by Brian Koberlein

What Shuts Down a Galaxy’s Star Formation?

Artist impression of 14 galaxies detected by ALMA as they appear in the very early, very distant universe. These galaxies are in the process of merging and will eventually form the core of a massive galaxy cluster. Credit: NRAO/AUI/NSF; S. Dagnello

In the 1920s, Edwin Hubble studied hundreds of galaxies. He found that they tended to fall into a few broad types. Some contained elegant spirals of bright stars, while others were spherical or elliptical with little or no internal structure. In 1926 he developed a classification scheme for galaxies, now known as Hubble’s Tuning Fork.

Hubble’s tuning fork diagram for galaxies. Credit: Edwin Hubble

When you look at Hubble’s scheme, it suggests an evolution of galaxies, beginning as an elliptical galaxy, then flattening and shifting into a spiral galaxy. While many saw this as a reasonable model, Hubble cautioned against jumping to conclusions. We now know ellipticals do not evolve into spirals, and the evolution of galaxies is complex. But Hubble’s scheme marks the beginning of the attempt to understand how galaxies grow, live, and die.

July 18, 2020July 18, 2020 by Matt Williams

The Moon Might Have Formed a Little Later than Originally Believed

According to the Giant Impact Hypothesis, the Moon formed when a Mars-sized object (named Theia) collided with Earth billion years ago, at a time when the Earth was still a ball of magma. This event not only led to the Earth-Moon system we recognize today, it is also beleived to have led to the differentiation of the Earth’s core region into an molten Outer Core and a solid Inner Core.

However, there has been an ongoing debate as to the timing of this impact and how long the subsequent formation of the Moon took place. According to a new study by a team of German researchers, the Moon formed from a magma ocean that took up to 200 million years to solidify. This means that the Moon finished forming about 4.425 billion years ago, or 100 million years later than previously thought.

July 17, 2020 by Andy Tomaswick

Curiosity Is Going To Spend Its Summer Driving Around a Dangerous Sandy Region on Mars

Do road trips actually require roads? Not if you’re NASA’s Curiosity rover, who is embarking on an extended 1 mile long road trip this summer up the side of Mount Sharp.

The rover will be moving between two “units” of Gale Crater, where it has been exploring since 2014. It’s wrapping up experiments in the “clay-bearing unit”, which resulted in the highest concentrations of clay found during the mission. It’s now moving to the “sulfate-bearing unit”, which is expected to contain an abundance of sulfates, such as gypsum and Epsom salts.

July 17, 2020July 16, 2020 by Paul M. Sutter

Supernovae shockwaves aren’t spherical

Artist’s impression of gamma-ray burst with orbiting binary star. Credit: University of Warwick/Mark Garlick

When stars blow up, they tend to release their energy in a roughly spherical shape. But much after the initial blast, the resulting shock waves can sometimes be elongated in one direction. A team of theorists used laboratory lasers to identify the potential culprit: magnetic fields.

July 16, 2020July 21, 2020 by Matt Williams

Do the TRAPPIST-1 Planets Have Atmospheres?

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In February of 2017, the scientific community rejoiced as NASA announced that a nearby star (TRAPPIST-1) had a system of no less than seven rocky planets! Since that time, astronomers have conducted all kinds of follow-up observations and studies in the hopes of learning more about these exoplanets. In particular, they have been attempting to learn if any of the planets located in the stars Habitable Zone (HZ) could actually be habitable.

Many of these studies have been concerned with whether or not the TRAPPIST-1 planets have sufficient water on their surfaces. But just as important is the question of whether or not any have viable atmospheres. In a recent study that provides an overview of all observations to date on TRAPPIST-1 planets, a team found that depending on the planet in question, they are likely to have good atmospheres, if any at all.

July 16, 2020July 16, 2020 by Evan Gough

A Stellar Stream of Stars, Stolen from Another Galaxy

The all-sky view that the Gaia survey would have of a simulated Milky-Way-like galaxy. [Credit: Sanderson et al. The Astrophysical Journal, January 6, 2020, DOI: 10.3847/1538-4365/ab5b9d]

Modern professional astronomers aren’t much like astronomers of old. They don’t spend every suitable evening with their eyes glued to a telescope’s eyepiece. You might be more likely to find them in front of a super-computer, working with AI and deep learning methods.

One group of researchers employed those methods to find a whole new collection of stars in the Milky Way; a group of stars which weren’t born here.

July 16, 2020July 16, 2020 by Matt Williams

Perseverance Has Been Put Inside its Atlas V Rocket

This summer – between July 30th and August 15th – NASA’s Perseverance rover will begin its long journey for Mars. Once it arrives (by February of 2021), it will join its sister mission, the Curiosity rover, and a slew of other robotic landers and orbiters that are busy characterizing the atmosphere and surface of the Red Planet. Ultimately, the goal of Perseverance is to determine if Mars once supported life (and maybe still does!)

Just last week (July 7th), the Perseverance rover and all the other elements of the Mars 2020 spacecraft were loaded aboard the United Launch Alliance (ULA) Atlas V rocket that will send it on its way. This included the aeroshell, cruise stage, and descent stage, which will be responsible for transporting the Perseverance rover during its six-month journey to Mars and depositing it on the surface.