exoplanets Archives

December 14, 2021December 14, 2021 by Evan Gough

Life on Earth Needed Iron. Will it be the Same on Other Worlds?

Earth as seen by the JUNO spacecraft in 2013. Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

A lot has to go right for a planet to support life. Some of the circumstances that allow life to bloom on any given planet stem from the planet’s initial formation. Here on Earth, circumstances meant Earth’s crust contains about 5% iron by weight.

A new paper looks at how Earth’s iron diminished over time and how that shaped the development of complex life here on Earth. Is iron necessary for complex life to develop on other worlds?

November 26, 2021November 26, 2021 by Evan Gough

Astronomers Find a Planet That Orbits its Star in Just 16 HOURS!

The newly discovered planet, designated TOI-2109b, is relatively close to its star, at a distance of only about 1.5 million miles out. Credits: Image: NASA, ESA and G. Bacon

Mercury is the speed champion in our Solar System. It orbits the Sun every 88 days, and its average speed is 47 km/s. Its average distance from the Sun is 58 million km (36 million mi), and it’s so fast it’s named after Mercury, the wing-footed God.

But what if instead of Mercury, Jupiter was closest to the Sun? And what if Jupiter was even closer to the Sun than Mercury and far hotter?

November 25, 2021November 25, 2021 by Matt Williams

A Space Telescope With one job: Find Habitable Planets at Alpha Centauri

Artist's impression of a hypothetical planet orbiting the star Alpha Centauri B, a member of the triple star system that is the closest to Earth. Credit: ESO

Alpha Centauri, the nearest star system to our Sun, is like a treasure trove with many scientific discoveries just waiting to be found. Part of what makes it so compelling is that our efforts to detect extrasolar planets there have failed to yield any concrete results to date. While the study of exoplanets has progressed exponentially in recent years, with 4,575 confirmed planets in 3,392 systems in the Milky Way (and even neighboring galaxies), astronomers are still having difficulty determining if anyone is next door.

In the coming decades, Breakthrough Initiatives plans to send a mission there known as Starshot, a lightsail craft that could make the journey in 20 years. On Nov. 16th, Breakthrough Initiatives announced another project for detecting exoplanets next door. It’s called the Telescope for Orbit Locus Interferometric Monitoring of our Astronomical Neighbourhood (TOLIMAN), a space telescope dedicated to finding rocky planets orbiting in Alpha Centauri’s circumsolar habitable zone (aka. “Goldilocks Zone”).

November 18, 2021November 18, 2021 by Evan Gough

Eggshell Planets Have a Thin Brittle Crust and No Mountains or Tectonics

'Eggshell planets’ are rocky worlds that have an ultra-thin outer brittle layer and little to no topography. Here, an artist’s rendition of such an exoplanet. (Image: NASA)

Planets without plate tectonics are unlikely to be habitable. But currently, we’ve never seen the surface of an exoplanet to determine if plate tectonics are active. Scientists piece together their likely surface structures from other evidence. Is there a way to determine what exoplanets might be eggshells, and eliminate them as potentially habitable?

The authors of a newly-published paper say there is.

November 2, 2021November 2, 2021 by Brian Koberlein

Moons are Planets too

Moons of the solar system compared to Earth. Credit: NASA

What makes a planet a planet? The answer turns out to be rather contentious. The official definition of a planet, as defined by the International Astronomical Union (IAU) is that a planet must satisfy three conditions:

It must orbit the Sun.
It must be in hydrostatic equilibrium.
It must have cleared its orbital neighborhood.

By this definition there are just eight planets in our solar system, most notably excluding Pluto. This has stirred all manner of controversy, even among astronomers. Several alternative definitions have been proposed, but a new study argues we should look to history for the solution.

October 19, 2021October 19, 2021 by Andy Tomaswick

Astronomers see a Moon-Forming Disk Around a Super-Jupiter

Recently, astronomers have been finding protoplanetary discs around certain stars. Their discovery has helped kick off a new work in planetary formation theory. But planets aren’t the objects that form from discs of material in space. Moons do too. Now, scientists led by Dr. Tomas Stolker of Leiden University and his team have delved deeper into the characteristics of a “protolunar” disc surrounding a “super Jupiter” exoplanet about 500 light-years away.

October 12, 2021October 7, 2021 by Paul M. Sutter

Rare Planet Found Orbiting Three Stars

GW Orionis, a triple star system with a mysterious gap in its surrounding dust rings. (Credit: ALMA (ESO/NAOJ/NRAO), ESO/Exeter/Kraus et al.)

It’s a hat-trick! Astronomers may have spotted the first ever known planet orbiting not one, not two, but three stars.

October 4, 2021October 4, 2021 by Matt Williams

A Technique to Find Oceans on Other Worlds

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

You could say that the study of extrasolar planets is in a phase of transition of late. To date, 4,525 exoplanets have been confirmed in 3,357 systems, with another 7,761 candidates awaiting confirmation. As a result, exoplanet studies have been moving away from the discovery process and towards characterization, where follow-up observations of exoplanets are conducted to learn more about their atmospheres and environments.

In the process, exoplanet researchers hope to see if any of these planets possess the necessary ingredients for life as we know it. Recently, a pair of researchers from Northern Arizona University, with support from the NASA Astrobiology Institute’s Virtual Planetary Laboratory (VPL), developed a technique for finding oceans on exoplanets. The ability to find water on other planets, a key ingredient in life on Earth, will go a long way towards finding extraterrestrial life.

October 3, 2021October 3, 2021 by Matt Williams

Astronomers Look at Super-Earths That had Their Atmospheres Stripped Away by Their Stars

Figure 1: Artist’s conceptual image showing the sizes of the planets observed in this study. The radius of TOI-1634 is 1.5 times larger than Earth’s radius and TOI-1685 is 1.8 times larger. The planets would appear red, due to the light from the red dwarf stars they orbit. (Credit: Astrobiology Center, NINS)

As the planets of our Solar System demonstrate, understanding the solar dynamics of a system is a crucial aspect of determining habitability. Because of its protective magnetic field, Earth has maintained a fluffy atmosphere for billions of years, ensuring a stable climate for life to evolve. In contrast, other rocky planets that orbit our Sun are either airless, have super-dense (Venus), or have very thin atmospheres (Mars) due to their interactions with the Sun.

In recent years, astronomers have been on the lookout for this same process when studying extrasolar planets. For instance, an international team of astronomers led by the National Astronomical Observatory of Japan (NAOJ) recently conducted follow-up observations of two Super-Earths that orbit very closely to their respective stars. These planets, which have no thick primordial atmospheres, represent a chance to investigate the evolution of atmospheres on hot rocky planets.

September 26, 2021September 26, 2021 by Matt Williams

Astronomers Detect Clouds on an Exoplanet, and Even Measure Their Altitude

The search for planets beyond our Solar System has grown immensely during the past few decades. To date, 4,521 extrasolar planets have been confirmed in 3,353 systems, with an additional 7,761 candidates awaiting confirmation. With so many distant worlds available for study (and improved instruments and methods), the process of exoplanet studies has been slowly transitioning away from discovery towards characterization.

For example, a team of international scientists recently showed how combining data from multiple observatories allowed them to reveal the structure and composition of an exoplanet’s upper atmosphere. The exoplanet in question is WASP-127b, a “hot Saturn” that orbits a Sun-like star located about 525 light-years away. These findings preview how astronomers will characterize exoplanet atmospheres and determine if they are conducive to life as we know it.