Evan Gough, Author at Universe Today

June 12, 2020June 12, 2020 by Evan Gough

Early Life Was Pumping Out Oxygen, But the Earth’s Mantle Was Absorbing it

The Earth straddling the limb of the Moon, as seen from above Compton crater on the lunar farside, taken by the Lunar Reconnaissance Orbiter spacecraft. Credit: NASA/GSFC/Arizona State University.

About 2.4 billion years ago, everything changed for Earth. That was the time of the Great Oxidation Event (GOE), when photosynthetic bacteria flooded the atmosphere with oxygen, banishing early, non-oxygen using lifeforms to the fringes of the Earth. The GOE laid the groundwork for the Earth we see today, dominated by complex, oxygen-breathing lifeforms.

But there’s one detail about the timing of the GOE that has scientists stumped. Photosynthetic bacteria were pumping out oxygen long before the actual GOE; hundreds of millions of years before, in fact.

Where did all the oxygen go?

June 11, 2020June 11, 2020 by Evan Gough

Titan is Drifting Away from Saturn Surprisingly Quickly

Titan in front of Saturn. Image Credit: NASA/JPL-Caltech/Space Science Institute

Where did Saturn’s bizarro-moon Titan form? Did it form where it is now, or has it migrated? We have decades of data to look back on, so scientists should have some idea.

A new study based on all that data says that Titan is drifting away from Saturn more quickly than thought, and that has implications for where the moon initially formed.

June 11, 2020June 11, 2020 by Evan Gough

It Should Be Easiest to Search for Young Earth-like Planets When They’re Completely Covered in Magma

Artist's impression of magma ocean planet. Credit: Mark Garlick

How did Earth evolve from an ocean of magma to the vibrant, life-supporting, blue jewel it is now? In its early years, the Earth was a blistering hot ball of magma. Now, 4.5 billion years later, it’s barely recognizable.

Is it possible to find exoplanets out there in the vast expanse, which are young molten globes much like young Earth was? How many of them can we expect to find? Where will we find them?

June 9, 2020June 9, 2020 by Evan Gough

Hubble Photo of Globular Cluster NGC 6441, One of the Most Massive in the Milky Way

NGC 6441 is one of the most luminous and massive globular clusters in the Milky Way. It also hosts fours pulsars. Image Credit: ESA/Hubble & NASA, G. Piotto

The Hubble Space Telescope has delivered another outstanding image. This one is of NGC 6441, a massive globular cluster in the constellation Scorpius. It’s one of the most massive ones in the Milky Way, and the stars in it have a combined mass of 1.6 million solar masses.

June 9, 2020June 9, 2020 by Evan Gough

Astronomers Have Found the Star/Exoplanet Combo That’s the Best Twin to the Sun/Earth

An artist's illustration of TOI 700d, an Earth-size exoplanet that TESS found in its star's habitable zone. Image Credit: NASA

At times, it seems like there’s an indundation of announcements featuring discoveries of “Earth-like” planets. And while those announcements are exciting, and scientifically noteworthy, there’s always a little question picking away at them: exactly how Earth-like are they, really?

After all, Earth is defined by its relationship with the Sun.

June 8, 2020June 8, 2020 by Evan Gough

Gamma Rays Detected Coming From the Crab Nebula

Crab Nebula (Credit:NASA, ESA and Allison Loll/Jeff Hester (Arizona State University). Acknowledgement: Davide De Martin (ESA/Hubble))

Most people with any interest in astronomy know about the Crab Nebula. It’s a supernova remnant in the constellation Taurus, and its image is all over the place. Google “Hubble images” and it’s right there with other crowd favorites, like the Pillars of Creation.

The Crab Nebula is one of the most-studied objects in astronomy. It’s the brightest source of gamma rays in the sky, and that fact is being used to establish the function of a new telescope called the Schwarschild-Couder Telescope.

June 8, 2020June 8, 2020 by Evan Gough

Much of the Lithium Here on Earth Came from Exploding White Dwarf Stars

A classical novae contains a white dwarf, and a larger companion star in orbit around it. The white dwarf attracts gas from its companion, leading to a massive explosion. Illustration Credit: David Hardy

The Big Bang produced the Universe’s hydrogen, helium, and a little lithium. Since then, it’s been up to stars (for the most part) to forge the rest of the elements, including the matter that you and I are made of. Stars are the nuclear forges responsible for creating most of the elements. But when it comes to lithium, there’s some uncertainty.

A new study shows where much of the lithium in our Solar System and our galaxy comes from: a type of stellar explosion called classical novae.

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?