Astronomy Archives

June 15, 2022June 15, 2022 by Matt Williams

There Could Be Four Hostile Civilizations in the Milky Way

This artists’s cartoon view gives an impression of how common planets are around the stars in the Milky Way. The planets, their orbits and their host stars are all vastly magnified compared to their real separations. A six-year search that surveyed millions of stars using the microlensing technique concluded that planets around stars are the rule rather than the exception. The average number of planets per star is greater than one.

In 1977, the Big Ear Radio Telescope at Ohio State University picked up a strong narrowband signal from space. The signal was a continuous radio wave that was very strong in intensity and frequency and had many expected characteristics of an extraterrestrial transmission. This event would come to be known as the Wow! Signal, and it remains the strongest candidate for a message sent by an extraterrestrial civilization. Unfortunately, all attempts to pinpoint the source of the signal (or detect it again) have failed.

This led many astronomers and theorists to speculate as to the origin of the signal and what type of civilization may have sent it. In a recent series of papers, amateur astronomer and science communicator Alberto Caballero offered some fresh insights into the Wow! Signal and extraterrestrial intelligence in our cosmic neighborhood. In the first paper, he surveyed nearby Sun-like stars to identify a possible source for the signal. In the second, he estimates the prevalence of hostile extraterrestrial civilizations in the Milky Way Galaxy and the likelihood that they’ll invade us.

June 15, 2022June 15, 2022 by Evan Gough

How Do Hot Jupiters Get So Close to Their Stars?

Thi illustration of a Hot Jupiter orbiting close to its star. Image Credit: ESA/ATG medialab, CC BY-SA 3.0 IGO

In this age of exoplanet discovery, we’ve discovered thousands of exoplanets of different types. The hot Jupiter is one of the most unusual types. There’s nothing like it in our Solar System.

Hot Jupiters are massive gas planets, and they attract a lot of attention because they’re so close to their stars and reach blistering temperatures. Their existence spawns a lot of questions about their formation and evolution. A new study is trying to answer some of those questions by determining hot Jupiters’ ages.

June 14, 2022June 14, 2022 by Evan Gough

A Geologic map of the Entire Moon has Been Released at 1:2,500,000-Scale

Chinese scientists took 10 years to create the most detailed map yet of the Moon. Image Credit: Jinzhu Ji et al. 2022.

Chinese scientists have created the most detailed map of the Moon yet. It took them 10 years and involved hundreds of researchers. The new map will be a boon to lunar exploration and for anyone who just wants to study our natural satellite in more detail.

June 12, 2022June 12, 2022 by Matt Williams

The World's Largest Liquid-Mirror Telescope Comes Online

Ask any astronomer, astrophysicist, or cosmologist, and they’ll probably tell you that a new age of astronomy is upon us! Between breakthroughs in gravitational-wave astronomy, the explosion in exoplanet studies, and the next-generation ground-based and space-based telescopes coming online, it’s pretty evident that we are on the verge of an era of near-continuous discovery! As always, major discoveries, innovations, and the things they enable inspire scientists and researchers to look ahead and take the next big step.

Take, for example, the research into liquid mirrors and advanced interferometers, which would rely on entirely new types of telescopes and light-gathering to advance the science of astronomy. A pioneering example is the newly-commissioned International Liquid Mirror Telescope (ILMT) telescope that just came online at Devasthal Peak, a 2,450 m (8,040 ft) tall mountain located in the central Himalayan range. Unlike conventional telescopes, the ILMT relies on a rapidly-rotating 4-meter (13 ft) mirror coated with a layer of mercury to capture cosmic light.

June 10, 2022June 2, 2022 by Paul M. Sutter

Do Supermassive Black Holes Prematurely end Star Formation in Some Galaxies?

Image of Sagittarius A, the complex radio source at the center of the Milky Way.

Some galaxies, like the Milky Way, have maintained regular star formation for billions of years. Others, like large elliptical galaxies, are “red and dead.” Star formation in those galaxies shut off long ago. Astronomers have long suspected the nefarious influence of supermassive black holes, and new research has found the smoking gun.

June 10, 2022June 10, 2022 by Carolyn Collins Petersen

A New Technique Finds a Bundle of Brown Dwarfs

brown dwarf artist's concept — An artist's conception of a T-dwarf brown dwarf object. Credit: Robert Hurt.

Astronomers have a brown dwarf problem. They should be seeing a lot more of these objects, which are cooler than stars but hotter than planets. Yet, there have only been about 40 directly imaged over the past few decades. Why aren’t astronomers finding more of them? It helps to remember that brown dwarfs are dim, low-temperature objects. They don’t stand out in a crowded starfield. If they’re too close to their stars, the starlight hides them from our view. They’re much better observed in the infrared part of the electromagnetic spectrum. All these characteristics make hunting for them difficult.

June 9, 2022June 9, 2022 by Evan Gough

Venus Does Have Craters. Here’s one

A radar image of Venus' Dickinson Crater. Image Credit: NASA/JPL-Caltech

As most everyone knows, Venus is called Earth’s twin, though its scorching temperatures and extreme surface pressure are more like an evil twin. For a twin and our closest planetary neighbour, we don’t know it very well. Venus’ dense clouds keep the planet’s surface hidden in visible-light observations.

It wasn’t until NASA’s Magellan spacecraft visited the planet in the early 1990s that we obtained a radar map of the surface. The survey showed almost 1,000 craters on the planet’s surface, finally visible through the sulphuric acid clouds that shroud the planet.

June 9, 2022June 9, 2022 by Matt Williams

ESA is About to Release its Third Giant Data Release From Gaia

The European Space Agency’s (ESA) Gaia Observatory is a mission dedicated to astrometry, a branch of astronomy where the velocity and proper motion of celestial objects are measured to learn more about the formation and evolution of the cosmos. For the past eight and a half years, this space-based has been studying over two billion objects in the Universe. This includes stars in the Milky Way but also planets, comets, asteroids, and distant galaxies. This information obtained by this mission will be used to create the most-detailed 3D catalog of the Milky Way ever.

Since the mission began in 2013, two major catalogs have been released, known as Gaia Data Release 1 and 2 (DR1 and DR2), accompanied by a smaller data set – Early Data Release 3 (EDR3). On June 13th, Gaia’s third full catalog (DR3) will be released, containing new and improved details for the two billion celestial objects it has been observing. The release will coincide with a virtual press event hosted by the Gaia Data Processing and Analysis Consortium (DPAC), where featured speakers will share the significance of this latest release and how it revolutionizes our understanding of the galaxy.

June 8, 2022June 8, 2022 by Evan Gough

Hubble Finds a Bunch of Galaxies That Webb Should Check out

Galaxies from the last 10 billion years witnessed in the 3D-DASH program, created using 3D-DASH/F160W and ACS-COSMOS/F814W imaging. Image Credit: Lamiya Mowla

The Universe is full of massive galaxies like ours, but astronomers don’t fully understand how they grew and evolved. They know that the first galaxies formed at least as early as 670 million years after the Big Bang. They know that mergers play a role in the growth of galaxies. Astronomers also know that supermassive black holes are involved in the growth of galaxies, but they don’t know precisely how.

A new Hubble survey of galaxies should help astronomers figure some of this out.

June 8, 2022June 8, 2022 by Matt Williams

NASA has Purchased 5 More Crew Dragon Missions, Keeping the ISS Going Until 2030

On November 15th, 2020, NASA and SpaceX made history when a crewed spacecraft – the Crew Dragon Resilience – lifted off from American soil and delivered four astronauts to the International Space Station (ISS). This mission (designated Crew-1) was a culminating achievement for NASA’s Commercial Crew Program (CCP) and effectively restored domestic launch capability to the U.S. for the first time since the Space Shuttle‘s retirement in 2011. As of April, SpaceX’s launch vehicles and spacecraft were used to mount the first all-private Axiom Mission-1 and the fourth flight of the CCP (Crew-4).

Building on this success, NASA recently filed a Notice Of Intent (NOI) to purchase five additional Crew Dragon spacecraft. This decision is based in large part on the delays suffered by Boeing – NASA’s other CCP commercial partner – and the development of its CST-100 Starliner spacecraft. But perhaps the most significant takeaway from this filing is how it reaffirms NASA’s commitment to the ISS until 2030. With the recent withdrawal of the Russians from the ISS program, the future of the station has been somewhat uncertain.