Scott Alan Johnston, Author at Universe Today

June 6, 2021June 6, 2021 by Scott Alan Johnston

Next up, Juno has Ganymede in its Sights

NASA’s Juno mission is set for a close encounter with the Solar System’s largest moon, Ganymede, on Monday. This will be the first flyby of the icy world since the Galileo and Cassini spacecraft jointly observed the moon in 2000. New Horizons also got a quick snap of Ganymede as it slingshotted around Jupiter on its way out to Pluto in 2007, but from a distance of 3.5 million kilometers away. Juno’s pass on Monday will get much closer, approaching within 1038 kilometers of the surface.

May 24, 2021May 24, 2021 by Scott Alan Johnston

Hubble Has Tracked Down the Source of 5 Different Fast Radio Bursts

In a new survey, astronomers using the Hubble Space Telescope have managed to pinpoint the location of several Fast Radio Bursts (FRBs). FRBs are powerful jets of energy that, until recently, had mysterious, unknown origins. The research team, which includes University of California Santa Cruz’ Alexandra Manning and Sunil Simha, as well as Northwestern University’s Wen-fai Fong, performed a survey of eight FRBs, from which they were able to determine that five of them originated from a spiral arm in their host galaxies.

May 20, 2021May 20, 2021 by Scott Alan Johnston

Larger Rocky Planets Might be Rare Because They Shrunk

Researchers at the Flatiron Institute’s Center for Computational Astrophysics published a paper last week that just might explain a mysterious gap in planet sizes beyond our solar system. Planets between 1.5 and 2 times Earth’s radius are strikingly rare. This new research suggests that the reason might be because planets slightly larger than this, called mini-Neptunes, lose their atmospheres over time, shrinking to become ‘super-Earths’ only slightly larger than our home planet. These changing planets only briefly have a radius the right size to fill the gap, quickly shrinking beyond it. The implication for planetary science is exciting, as it affirms that planets are not static objects, but evolving and dynamic worlds.

May 16, 2021May 16, 2021 by Scott Alan Johnston

What’s the Best Way to Water Plants in Space?

Humans have maintained a continuous presence in space on the International Space Station (ISS) for more than 20 years now. It is our longest-running and most comprehensive experiment in long-duration spaceflight. But the ISS is continually supplied with consumables – food, water, and oxygen – so astronauts are largely reliant on Earth. If Humanity is ever going to live and work in space long term, we’re going to have to learn to be more self-reliant – and that means growing food in space.

May 8, 2021May 8, 2021 by Scott Alan Johnston

Volcanoes on Mars Might Still be Active

Back in March, NASA’s InSight lander detected two large quakes from a geologically active region of Mars called the Cerberus Fossae. Now, using imagery from the Mars Reconnaissance Orbiter, which circles the red planet at an altitude of about 300km, researchers have discovered that the Cerberus Fossae region holds the most recent evidence of volcanic activity ever seen on Mars.

May 2, 2021May 2, 2021 by Scott Alan Johnston

Black Hole-Neutron Star Collisions Could Finally Settle the Different Measurements Over the Expansion Rate of the Universe

If you’ve been following developments in astronomy over the last few years, you may have heard about the so-called “crisis in cosmology,” which has astronomers wondering whether there might be something wrong with our current understanding of the Universe. This crisis revolves around the rate at which the Universe expands: measurements of the expansion rate in the present Universe don’t line up with measurements of the expansion rate during the early Universe. With no indication for why these measurements might disagree, astronomers are at a loss to explain the disparity.

The first step in solving this mystery is to try out new methods of measuring the expansion rate. In a paper published last week, researchers at University College London (UCL) suggested that we might be able to create a new, independent measure of the expansion rate of the Universe by observing black hole-neutron star collisions.

April 30, 2021April 30, 2021 by Scott Alan Johnston

China Launches the Core Module of Its New Space Station

Early on Thursday, a Long March 5B rocket – currently the most powerful of China’s space launch vehicles – blasted off from Wenchang, carrying the first major component of an ambitious new modular space station.

The station module, dubbed Tianhe (Harmony of the Heavens), marks the next big step in China’s human spaceflight program in Low Earth Orbit (LEO). Barred from participating in the International Space Station (ISS) by US law, which forbids cooperation in space between the two countries, China has been developing its own LEO capabilities for over a decade now.

April 23, 2021April 23, 2021 by Scott Alan Johnston

Perseverance Successfully Extracts Oxygen From the Martian Atmosphere. About 10 Minutes of Breathing Time for an Astronaut

Humanity achieved an incredible series of new milestones on Mars this week. It began on Monday April 19th, when the Ingenuity helicopter demonstrated the first-ever powered, controlled flight on another world. And now, for the first time, the Perseverance rover has used ingredients from the Martian atmosphere to create breathable oxygen, in a test that might pave the way for future astronauts to ‘live off the land’ on the Red Planet.

April 17, 2021April 17, 2021 by Scott Alan Johnston

When Stars Get Too Close to Each Other, They Cast Out Interstellar Comets and Asteroids

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

In October 2017, humanity caught its first-ever glimpse of an interstellar object – a visitor from beyond our solar system – passing nearby the Sun. We named it Oumuamua, and its unusual properties fascinated and confounded astronomers. Less than two years later, amateur astronomer Gennady Borisov found a second interstellar object: a comet-like body that began to disintegrate as it passed within 2 AU of the Sun (1 AU equals the distance from Earth to the Sun). Where do these interstellar objects come from? How common are they? With a sample size of just two, it’s difficult to make any generalizations just yet. On the other hand, given what we know about star formation, we can begin to make some inferences about the likely origins of these objects, and what we are likely to see of them in the future.

April 15, 2021April 15, 2021 by Scott Alan Johnston

Ground-Based Lasers Could Push Space Debris off Collision-Course Orbits

Researchers at the Australian National University (ANU) are finding new uses for the laser-based technology that sharpens telescope imagery – called adaptive optics – and it just might help mitigate the world’s growing space debris problem. Purpose-built lasers could give derelict satellites a slight ‘push’ of photons, imparting just enough energy to change the debris’s orbit and prevent an impending collision.