Extrasolar Planets Archives

September 9, 2022September 9, 2022 by Matt Williams

Astronomers Create the First 3D Model of a Planet Orbiting in a Binary System

Artist's conception of an exoplanet about twice the size of Jupiter, the star it orbits, and the binary companion in the distance. Credit: Sophia Dagnello, NRAO/AUI/NSF.

To date, 5,084 extrasolar planets have been confirmed in 3,811 planetary systems, with another 8,912 candidates awaiting confirmation. These discoveries have provided astronomers with a detailed sampling of the types of planets that exist in our Universe, ranging from gas giants several times the size of Jupiter to smaller, rocky bodies like Earth. So far, the vast majority of these have been discovered using indirect methods – like the Transit Method (Transit Photometry) and the Radial Velocity Method (Doppler Spectroscopy) – while the remainder has been detected using various other means.

In a recent study, an international team of astronomers used the National Science Foundation’s (NSF) Very Long Baseline Array (VLBA) network to detect a Jupiter-like planet orbiting in a binary system (GJ 896AB) located about 20 light-years from Earth. Using a method known as Astrometry, the team managed to detect this planet by the “wobble” it makes as it orbits the larger of the system’s two stars. Moreover, this method allowed the team to create the first 3-dimensional architecture of a binary system and a planet that orbits one of its stars.

August 26, 2022August 26, 2022 by Matt Williams

Astronomers Find a Waterworld Planet With Deep Oceans in the Habitable Zone

Artist's rendering of a super-Earth-type exoplanet, TOI 1452 b. Credit: Benoit Gougeon, Université de Montréal.

In the search for extrasolar planets, astronomers and astrobiologists generally pursue a policy of “follow the water.” This comes down to searching for planets that orbit with a star’s circumsolar habitable zone (HZ), where conditions are warm enough that liquid water can flow on its surface. The reason is simple: water is the only known solvent capable of supporting life and is required by all life on Earth. However, since the 1970s, scientists have speculated that there may be a class of rocky planets in our Universe that are completely covered in water.

With the explosion in confirmed exoplanets, scientists have been eager to find examples of this type of planet, so they study them more closely. Thanks to an international team of researchers led by the Institute for Research on Exoplanets (iREx) at the Université de Montréal, an exoplanet orbiting within its system’s HZ was recently discovered that could be completely covered in deep oceans. This “ocean world” (aka. “Waterworld”) could reveal things about the nature of habitability when it is the subject of follow-up observations using the James Webb Space Telescope (JWST).

August 11, 2022August 11, 2022 by Matt Williams

The Youngest Exoplanet Ever Seen?

Credit: ALMA (ESO/NAOJ/NRAO), S. Dagnello (NRAO/AUI/NSF)

According to the most widely-accepted theory by astronomers, planetary systems begin as massive clouds of gas and dust (aka. a nebula) that experience gravitational collapse at the center to form new stars. The remaining matter in the system forms a “circumplanetary disk” around the star, which gradually accretes to form young planets. Studying disks in the earliest stages of planetary formation could help answer some hard questions about how the Solar System formed over 4.5 billion years ago.

Studying these disks requires observatories capable of capturing light in the far-infrared part of the spectrum – precisely what the Atacama Large Millimeter/submillimeter Array (ALMA) was built for. While studying a young star (AS 209) located about 395 light-years from Earth in the constellation Ophiuchus, a team of scientists observed a circumplanetary disk that appeared to have a Jupiter-mass planet embedded in it. This could constitute the youngest exoplanet ever detected, and its continued study could provide a treasure-trove of data for astronomers.

July 22, 2022July 22, 2022 by Matt Williams

NASA Wants Your Help Designing a Starshade to Observe Exoplanets

Artist's concept of the prototype starshade, a giant structure designed to block the glare of stars so that future space telescopes can take pictures of planets. Credit: NASA/JPL

The field of exoplanet study has come a long way in recent decades. To date, 5,063 exoplanets have been confirmed in 3,794 systems beyond our own, with another 8,819 candidates awaiting confirmation. In the coming years, tens of thousands of more planets are expected to be found, thanks to next-generation observatories. The ultimate goal in this search is to find planets that are “Earth-like,” meaning they have a good chance of supporting life. This is no easy task, as rocky planets located within their parent star’s habitable zones (HZs) tend to orbit closely, making them harder to see.

To make this process easier, NASA is designing a hybrid observatory consisting of a “Starshade” that will block out a star’s light so that a ground-based telescope can directly image planets orbiting it. The concept is known as the Hybrid Observatory for Earth-like Exoplanets (HOEE), and NASA is looking for public input to make it a reality. To that end, they have launched the Ultralight Starshade Structural Design Challenge, where participants are asked to develop a design for a lightweight starshade structure that could be used as part of the HOEE concept.

June 30, 2022June 30, 2022 by Matt Williams

Tidal Heating Could Make Exomoons Much More Habitable (and Detectable)

An artist's illustration of the Kepler 1625 system. The star in the distance is called Kepler 1625. The gas giant is Kepler 1625B, and the exomoon orbiting it is unnamed. The moon is about as big as Neptune, but is a gas moon. Image: NASA, ESA, and L. Hustak (STScI)

Within the Solar System, most of our astrobiological research is aimed at Mars, which is considered to be the next-most habitable body beyond Earth. However, future efforts are aimed at exploring icy satellites in the outer Solar System that could also be habitable (like Europa, Enceladus, Titan, and more). This dichotomy between terrestrial (rocky) planets that orbit within their a system’s Habitable Zones (HZ) and icy moons that orbit farther from their parent stars is expected to inform future extrasolar planet surveys and astrobiology research.

In fact, some believe that exomoons may play a vital role in the habitability of exoplanets and could also be a good place to look for life beyond the Solar System. In a new study, a team of researchers investigated how the orbit of exomoons around their parent bodies could lead to (and place limits on) tidal heating – where gravitational interaction leads to geological activity and heating in the interior. This, in turn, could help exoplanet-hunters and astrobiologists determine which exomoons are more likely to be habitable.

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.

May 27, 2022February 17, 2023 by Matt Williams

A new Quantum Technique Could Enable Telescopes the Size of Planet Earth

These annotated images, obtained with the GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) between March and July 2021, show stars orbiting very close to Sgr A*, the supermassive black hole at the heart of the Milky Way. One of these stars, named S29, was observed as it was making its closest approach to the black hole at 13 billion kilometres, just 90 times the distance between the Sun and Earth. Another star, named S300, was detected for the first time in the new VLTI observations. To obtain the new images, the astronomers used a machine-learning technique, called Information Field Theory. They made a model of how the real sources may look, simulated how GRAVITY would see them, and compared this simulation with GRAVITY observations. This allowed them to find and track stars around Sagittarius A* with unparalleled depth and accuracy.

There’s a revolution underway in astronomy. In fact, you might say there are several. In the past ten years, exoplanet studies have advanced considerably, gravitational wave astronomy has emerged as a new field, and the first images of supermassive black holes (SMBHs) have been captured. A related field, interferometry, has also advanced incredibly thanks to highly-sensitive instruments and the ability to share and combine data from observatories worldwide. In particular, the science of very-long baseline interferometry (VLBI) is opening entirely new realms of possibility.

According to a recent study by researchers from Australia and Singapore, a new quantum technique could enhance optical VLBI. It’s known as Stimulated Raman Adiabatic Passage (STIRAP), which – in combination with pre-distributed entanglement – allows quantum information to be transferred without losses. When imprinted into a quantum error correction code, this technique could allow for VLBI observations into previously inaccessible wavelengths. Once integrated with next-generation instruments, this technique could allow for more detailed studies of black holes, exoplanets, the Solar System, and the surfaces of distant stars.

May 21, 2022May 21, 2022 by Matt Williams

The Closeby Habitable Exoplanet Survey (CHES) Could Detect Exoplanets Within a few Dozen Light-Years of Earth Using Astrometry

Artist's concept of Earth-like exoplanets, which (according to new research) need to strike the careful balance between water and landmass. Credit: NASA

As of this article’s writing, NASA has indicated that 5,030 extrasolar planets have been confirmed in 3,772 systems, with another 8,974 candidates awaiting confirmation. With next-generation instruments like the James Webb Space Telescope (JWST) coming online, the number and diversity of confirmed exoplanets are expected to grow exponentially. In particular, astronomers anticipate that the number of known terrestrial planets and Super-Earths will drastically increase.

In the coming years, the opportunities for exoplanet studies will increase considerably as thousands more are discovered using various methods. In a recent study, a team led by the Chinese Academy of Sciences (CAS) described a new space-telescope concept known as the Closeby Habitable Exoplanet Survey (CHES). This proposed observatory will search for Earth-like planets in the habitable zones (HZs) of Sun-like stars within approximately 33 light-years (10 parsecs) using a method known as micro-arcsecond relative astrometry.

March 20, 2022March 20, 2022 by Matt Williams

Why Would an Alien Civilization Send Out Von Neumann Probes? Lots of Reasons, says a new Study

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In 1948-49, mathematician, physicist, computer scientist, and engineer John von Neumann introduced the world to his idea of “Universal Assemblers,” a species of self-replicating robots. Von Neumann’s ideas and notes were later compiled in a book titled “Theory of self-reproducing automata,” published in 1966 (after his death). In time, this theory would have implications for the Search for Extraterrestrial Intelligence (SETI), with theorists stating that advanced intelligence must have deployed such probes already.

The reasons and technical challenges of taking the self-replicating probe route are explored in a recent paper by Gregory L. Matloff, an associate professor at the New York City College of Technology (NYCCT). In addition to exploring why an advanced species would opt to explore the galaxy using Von Neumann probes (which could include us someday), he explored possible methods for interstellar travel, strategies for exploration, and where these probes might be found.

March 19, 2022March 19, 2022 by Matt Williams

Machine Learning Will be one of the Best Ways to Identify Habitable Exoplanets

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

The field of extrasolar planet studies is undergoing a seismic shift. To date, 4,940 exoplanets have been confirmed in 3,711 planetary systems, with another 8,709 candidates awaiting confirmation. With so many planets available for study and improvements in telescope sensitivity and data analysis, the focus is transitioning from discovery to characterization. Instead of simply looking for more planets, astrobiologists will examine “potentially-habitable” worlds for potential “biosignatures.”

This refers to the chemical signatures associated with life and biological processes, one of the most important of which is water. As the only known solvent that life (as we know it) cannot exist, water is considered the divining rod for finding life. In a recent study, astrophysicists Dang Pham and Lisa Kaltenegger explain how future surveys (when combined with machine learning) could discern the presence of water, snow, and clouds on distant exoplanets.