Evan Gough, Author at Universe Today

June 6, 2020June 6, 2020 by Evan Gough

A New Telescope is Ready to Start Searching for Answers to Explain Dark Energy

An illustration of cosmic expansion. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

Back in 2015, construction began on a new telescope called the Dark Energy Spectroscopic Instrument (DESI). Later this year, it will begin its five-year mission. Its goal? To create a 3D map of the Universe with unprecedented detail, showing the distribution of matter.

That detailed map will allow astronomers to investigate important aspects of cosmology, including dark energy and its role in the expansion of the Universe.

June 5, 2020February 17, 2023 by Evan Gough

Supermassive Black Holes Grew by Consuming Gas and Entire Stars

This artist’s impression shows the surroundings of a supermassive black hole, typical of that found at the heart of many galaxies. The black hole itself is surrounded by a brilliant accretion disc of very hot, infalling material and, further out, a dusty torus. There are also often high-speed jets of material ejected at the black hole’s poles that can extend huge distances into space. Observations with ALMA have detected a very strong magnetic field close to the black hole at the base of the jets and this is probably involved in jet production and collimation.

Where do they come from, those beguiling singularities that flummox astrophysicists—and the rest of us. Sure, we understand the processes behind stellar mass black holes, and how they form from the gravitational collapse of a star.

But what about the staggering behemoths at the center of galaxies, those supermassive black holes (SMBH) that can grow to be billions of times more massive than our Sun?

How do they get so big?

June 5, 2020June 5, 2020 by Evan Gough

Interstellar Oumuamua Was a Dark Hydrogen Iceberg

Artist’s impression of the first interstellar asteroid/comet, "Oumuamua". This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

When Canadian astronomer Robert Weryk discovered `Oumuamua passing through our Solar System with the Pan-STARRS telescope, in October 2017, it caused quite a stir. It was the first interstellar object we’d ever seen coming through our neighbourhood. The excitement led to speculation: what could it be?

There was lots of fun conjecture on its origins. Was it an alien spacecraft? A solar sail? Or something more prosaic?

June 5, 2020June 5, 2020 by Evan Gough

Finally! Mars InSight’s Mole is Now Underground

On June 4th NASA reported that the Mole is finally making some headway. But the instrument is not producing any science yet. Image Credit: NASA/DLR/JPL

It looks like the InSight Lander’s Mole instrument is making some progress. After months of perseverance, the team operating the instrument has succeeded in getting the Mole at least some distance into the ground.

That’s a victory in itself, considering all the setbacks there’ve been. But it’s too soon to celebrate: there’s quite a ways to go before the Mole can deliver any science.

June 4, 2020June 4, 2020 by Evan Gough

Astronomers Find the Source of the Huge Bubbles of Gas Flowing Out of the Milky Way, Still No Idea What Caused Them

Astronomers used the WHAM telescope to measure huge outflows of gas extending from the Milky Way’s center known as the Fermi Bubbles. They were able to measure the velocity, density and pressure of the gas for the first time, confirming and extending previous measurements made by using a distant quasar as a light source to look through and measure the gas. IMAGE BY DHANESH KRISHNARAO AND NASA

There’s an unusual paradox hampering research into parts of the Milky Way. Dense gas blocks observations of the galactic core, and it can be difficult to observe in visible light from our vantage point. But distant galaxies don’t always present the same obstacles. So in some ways, we can observe distant galaxies better than we can observe our own.

In order to gain a better understanding of the Galactic Center (GC) and the Interstellar Medium (ISM), a team of astronomers used a telescope called the Wisconsin H-Alpha Mapper (WHAM) to look into the core of the Milky Way in part of the optical light spectrum.

June 4, 2020June 4, 2020 by Evan Gough

Evidence that Mars Used to Have a Ring

An illustration of Mars with a debris ring. Image Credit: SETI

Mars only has two moons: Phobos and Deimos. They’re strange, for moons, little more than lumpy, potato-shaped chunks of rock. They’re much too small for self-gravitation to have made them round. And one of them, Deimos, has an unusually tilted orbit.

What does that slight tilt tell us about Deimos? About Mars?

June 3, 2020June 3, 2020 by Evan Gough

About 3.5 Million Years Ago, a Stream of Gas Outside the Milky Way Would Have Lit Up the Night Sky

An illustration of our hominid ancestors, likely Australopithecus, walking at night, under the lit up stream of gas about 3.5 million years ago. Image Credit: NASA, ESA, G. Cecil (UNC, Chapel Hill), and J. DePasquale (STScI)

It’s a truism to point out that modern humans have only been around for the blink of an eye, relative to the age of the Universe. But the Universe was an active place long before we were around to observe all of that activity. And about 3.5 million years ago, it’s possible—if only remotely—that our ancient ancestors noticed something change in the night sky.

Would it have stirred something inside them? Impossible to know.

June 3, 2020June 3, 2020 by Evan Gough

Barred Spiral NGC 3895 Captured by Hubble

Far away in the Ursa Major constellation is a swirling galaxy that would not look out of place on a coffee made by a starry-eyed barista. NGC 3895 is a barred spiral galaxy that was first spotted by William Herschel in 1790 and was later observed by the NASA/ESA Hubble Space Telescope. Hubble's orbit high above the Earth's distorting atmosphere allows astronomers to make the very high resolution observations that are essential to opening new windows on planets, stars and galaxies — such as this beautiful view of NGC 3895. The telescope is positioned approximately 570 km above the ground, where it whirls around Earth at 28 000 kilometres per hour and takes 96 minutes to complete one orbit.

NGC 3895 is a barred spiral galaxy in the Ursa Major constellation. It’s about 145 million light years away from our home, the Milky Way, and its diameter is about 45,000 light years. William Herschel discovered it way back in 1790.

Now the Hubble Space Telescope has given us another gorgeous image of it. Thanks Hubble!

June 2, 2020June 2, 2020 by Evan Gough

New Simulations Show How Black Holes Grow, Through Mergers and Accretion

Artist's impression of two merging black holes. Credit: Bohn, Throwe, Hébert, Henriksson, Bunandar, Taylor, Scheel/SXS

One of the most pressing questions in astronomy concerns black holes. We know that massive stars that explode as supernovae can leave stellar mass black holes as remnants. And astrophysicists understand that process. But what about the supermassive black holes (SMBHs) like Sagittarius A-star (Sgr A*,) at the heart of the Milky Way?

SMBHs can have a billion solar masses. How do they get so big?

June 2, 2020June 2, 2020 by Evan Gough

The Meteor Impact that Wiped Out the Dinosaurs Created a Vast Underground Hydrothermal System

A Three-dimensional cross-section of the hydrothermal system in the Chicxulub impact crater and its seafloor vents. The system has the potential for harboring microbial life. Illustration by Victor O. Leshyk for the Lunar and Planetary Institute.

The Chicxulub impact event was an enormous catastrophe that left a huge imprint on the Earth’s surface. Not only did it cause the mass extinction of the dinosaurs, it left a crater 180 km (112 miles) in diameter, and deposited a worldwide layer of concentrated iridium in the Earth’s crust.

But a new study shows that the impact also left its mark deep underground, in the form of a vast hydrothermal system that modified a massive chunk of the Earth’s crust.