Astronomers Measure the Atmosphere on a Planet Hundreds of Light-Years Away

An artist's conception of the hot Jupiter WASP-79b. (Image credit: NASA)

The field of extrasolar planet research has advanced by leaps and bounds over the past fifteen years. To date, astronomers have relied on space-based and ground-based telescopes to confirm the existence of 4,566 exoplanets in 3,385 systems, with another 7,913 candidates awaiting confirmation. More importantly, in the past few years, the focus of exoplanet studies has slowly shifted from the process of discovery towards characterization.

In particular, astronomers are making great strides when it comes to the characterization of exoplanet atmospheres. Using the Gemini South Telescope (GST) in Chile, an international team led by Arizona State University (ASU) was able to characterize the atmosphere of a “hot Jupiter” located 340 light-years away. This makes them the first team to directly measure the chemical composition of a distant exoplanet’s atmosphere, a significant milestone in the hunt for habitable planets beyond our Solar System.

Continue reading “Astronomers Measure the Atmosphere on a Planet Hundreds of Light-Years Away”

Rocky Planets Might Need to be the Right age to Support Life

This artist’s impression shows a Super-Earth orbiting a Sun-like star. HD 85512 in the southern constellation of Vela (The Sail). This planet is one of sixteen super-Earths discovered by the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory. This planet is about 3.6 times as massive as the Earth lis at the edge of the habitable zone around the star, where liquid water, and perhaps even life, could potentially exist. Credit: ESO

Extrasolar planets are being discovered at a rapid rate, with 4,531 planets in 3,363 systems (with another 7,798 candidates awaiting confirmation). Of these, 166 have been identified as rocky planets (aka. “Earth-like”), while another 1,389 have been rocky planets that are several times the size of Earth (“Super-Earths). As more and more discoveries are made, the focus is shifting from the discovery process towards characterization.

In order to place tighter constraints on whether any of these exoplanets are habitable, astronomers and astrobiologists are looking for ways to detect biomarkers and other signs of biological processes. According to a new study, astronomers and astrobiologists should look for indications of a carbon-silicate cycle. On Earth, this cycle ensures that our climate remains stable for eons and could be the key to finding life on other planets.

Continue reading “Rocky Planets Might Need to be the Right age to Support Life”

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.

Continue reading “A Technique to Find Oceans on Other Worlds”

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.

Continue reading “Astronomers Look at Super-Earths That had Their Atmospheres Stripped Away by Their Stars”

Ocean Worlds With Hydrogen-Rich Atmospheres Could be the Perfect Spots for Life

Artist's impression of the surface of a hycean world. Hycean worlds are still hypothetical, and have large oceans and thick hydrogen-rich atmospheres that trap heat. They could be habitable even if they're outside the traditional habitable zone. Credit: University of Cambridge

The search for planets beyond our Solar System (extrasolar planets) has grown by leaps and bounds in the past decade. A total of 4,514 exoplanets have been confirmed in 3,346 planetary systems, with another 7,721 candidates awaiting confirmation. At present, astrobiologists are largely focused on the “low hanging fruit” approach of looking for exoplanets that are similar in size, mass, and atmospheric composition to Earth (aka. “Earth-like.”)

However, astrobiologists are also interested in finding examples of “exotic life,” the kind that emerged under conditions that are not “Earth-like.” For example, a team of astronomers from the University of Cambridge recently conducted a study that showed how life could emerge on ocean-covered planets with hydrogen-rich atmospheres (aka. “Hycean” planets). These findings could have significant implications for exoplanet studies and the field of astrobiology.

Continue reading “Ocean Worlds With Hydrogen-Rich Atmospheres Could be the Perfect Spots for Life”

There are Probably Many More Earth-Sized Worlds Than Previously Believed

This illustration depicts a planet partially hidden in the glare of its host star and a nearby companion star. After examining a number of binary stars, astronomers have concluded that Earth-sized planets in many two-star systems might be going unnoticed by transit searches, which look for changes in the light from a star when a planet passes in front of it. The light from the second star makes it more difficult to detect the changes in the host star’s light when the planet passes in front of it. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva (Spaceengine)

In the past decade, the discovery of extrasolar planets has accelerated immensely. To date, 4,424 exoplanets have been confirmed in 3,280 star systems, with another 7,453 awaiting confirmation. So far, most of these planets have been gas giants, with about 66% being similar to Jupiter or Neptune, while another 30% have been giant rocky planets (aka. “Super-Earths). Only a small fraction of confirmed exoplanets (less than 4%) have been similar in size to Earth.

However, according to new research by astronomers working at NASA Ames Research Center, it is possible that Earth-sized exoplanets are more common than previously thought. As they indicated in a recent study, there could be twice as many rocky exoplanets in binary systems that are obscured by the glare of their parent stars. These findings could have drastic implications in the search for potentially habitable worlds since roughly half of all stars are binary systems.

Continue reading “There are Probably Many More Earth-Sized Worlds Than Previously Believed”

NASA Continues to Try and Rescue Failing Hubble

Will China's new space telescope out-perform the Hubble? Image:
The Hubble Space Telescope. Image: NASA

Things are not looking very good for the Hubble Space Telescope right now. On Sunday, June 13th, the telescope’s payload computer suddenly stopped working, prompting the main computer to put the telescope into safe mode. While the telescope itself and its science instruments remain in working order, science operations have been suspended until the operations team can figure out how to get the payload computer back online.

While attempting to restart the computer, the operations team has also tried to trace the issue to specific components in the payload computer and switch to their backup modules. As of June 30th, the team began looking into the Command Unit/Science Data Formatter (CU/SDF) and the Power Control Unit (PCU). Meanwhile, NASA is busy preparing and testing procedures to switch to backup hardware if either of these components are the culprit.

Continue reading “NASA Continues to Try and Rescue Failing Hubble”

To Take the Best Direct Images of Exoplanets With Space Telescopes, we’re Going to Want Starshades

Between 2021 and 2024, the James Webb (JWST) and Nancy Grace Roman (RST) space telescopes will be launched to space. As the successors to multiple observatories (like Hubble, Kepler, Spitzer, and others), these missions will carry out some of the most ambitious astronomical surveys ever mounted. This will range from the discovery and characterization of extrasolar planets to investigating the mysteries of Dark Matter and Dark Energy.

In addition to advanced imaging capabilities and high sensitivity, both instruments also carry coronagraphs – instruments that suppress obscuring starlight so exoplanets can be detected and observed directly. According to a selection of papers recently published by the Journal of Astronomical Telescopes, Instruments, and Systems (JATIS), we’re going to need more of these instruments if we truly want to really study exoplanets in detail.

Continue reading “To Take the Best Direct Images of Exoplanets With Space Telescopes, we’re Going to Want Starshades”

Most Exoplanets won’t Receive Enough Radiation to Support an Earth-Like Biosphere

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

To date, astronomers have confirmed the existence of 4,422 extrasolar planets in 3,280 star systems, with an additional 7,445 candidates awaiting confirmation. Of these, only a small fraction (165) have been terrestrial (aka. rocky) in nature and comparable in size to Earth – i.e., not “Super-Earths.” And even less have been found that are orbiting within their parent star’s circumsolar habitable zone (HZ).

In the coming years, this is likely to change when next-generation instruments (like James Webb) are able to observe smaller planets that orbit closer to their stars (which is where Earth-like planets are more likely to reside). However, according to a new study by researchers from the University of Napoli and the Italian National Institute of Astrophysics (INAF), Earth-like biospheres may be very rare for exoplanets.

Continue reading “Most Exoplanets won’t Receive Enough Radiation to Support an Earth-Like Biosphere”

A New Technique for “Seeing” Exoplanet Surfaces Based on the Content of their Atmospheres

This artist’s impression shows the planet K2-18b, it’s host star and an accompanying planet in this system. K2-18b is now the only super-Earth exoplanet known to host both water and temperatures that could support life. UCL researchers used archive data from 2016 and 2017 captured by the NASA/ESA Hubble Space Telescope and developed open-source algorithms to analyse the starlight filtered through K2-18b’s atmosphere. The results revealed the molecular signature of water vapour, also indicating the presence of hydrogen and helium in the planet’s atmosphere.

In November of 2021, the James Webb Space Telescope (JWST) will make its long-awaited journey to space. This next-generation observatory will observe the cosmos using its advanced infrared suite and reveal many never-before-seen things. By 2024, it will be joined the Nancy Grace Roman Space Telescope (RST), the successor to the Hubble mission that will have 100 times Hubble’s field of view and faster observing time.

These instruments will make huge contributions to many fields of research, not the least of which is the discovery and characterization of extrasolar planets. But even with their advanced optics and capabilities, these missions will not be able to examine the surfaces of exoplanets in any detail. However, a team of the UC Santa Cruz (UCSC) and the Space Science Institute (SSI) have developed the next best thing: a tool for detecting an exoplanet surface without directly seeing it.

Continue reading “A New Technique for “Seeing” Exoplanet Surfaces Based on the Content of their Atmospheres”