On September 26th, at 23:14 UTC (07:14 PM EST; 04:14 PM PST), NASA’s Double Asteroid Redirect Test (DART) spacecraft successfully struck the 160-meter (525 ft) moonlet Dimorphos that orbits the larger Didymos asteroid. The event was live-streamed all around the world and showed footage from DART’s Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) as it rapidly approached Dimorphos. In the last few seconds, DART was close enough that individual boulders could be seen on the moonlet’s surface.
About 38 seconds after impact, the time it took the signal to reach Earth, the live stream ended, signaling that DART had successfully impacted Dimorphos and was destroyed in the process. Meanwhile, teams of astronomers stretching from the Indian Ocean to the Arabian Peninsula watched the impact with their telescopes. One, in particular – the Les Makes Observatory on the island of Le Reunion in the Indian Ocean – captured multiple images of the impact. These were used to create a real-time video and show the asteroid brightening as it was pushed away, followed by material ejected from the surface.
In July 2016, NASA’s Juno space probe reached Jupiter, becoming the second spacecraft in history to orbit the gas giant (the first being the Galileo probe that orbited Jupiter from 1995 to 2003). The data it has sent back has led to new revelations about the Jovian atmosphere, magnetosphere, gravitational field, structure, and composition. While its primary mission was intended to only last until 2018, a mission extension means that Juno will continue to orbit Jupiter’s poles (a perijove maneuver) and send back stunning images and data until 2025.
Recently, a team of citizen scientists led by mathematician and software developer Gerald Eichstädt used images taken by the probe’s visible-light camera/telescope (the JunoCam) to create a 3D animation of Jupiter’s upper atmosphere. Eichstädt’s animation was presented at the 2022 Europlanet Science Congress (EPSC), which took place from September 18 – 23 in Granada, and shows the relative heights of the cloud tops of Jupiter that reveal delicately textured swirls and peaks. Eichstädt’s work also showcased the potential for citizen science and public engagement with today’s missions.
Over sixty years ago, the first search for extraterrestrial intelligence (SETI), known as Project Ozma, was conducted. This campaign was led by legendary astronomer Frank Drake, which relied on the 85-1 Tatel Telescope at the Green Bank Observatory in West Virginia to listen to Tau Ceti and Epsilon Eridani for any signs of radio transmissions. Since then, the field of SETI has become more sophisticated thanks to more advanced radio telescopes, improved data analysis, and international collaboration. In the coming years, SETI will also benefit from advances in exoplanet studies and next-generation instruments and surveys.
In addition to examining exoplanets for signs of technological activity (aka. “technosignatures”), there are also those who recommend that we look for them here at home. Examples include the Galileo Project, which is dedicated to studying interstellar objects (ISOs) and unidentified aerial phenomena (UAP). There’s also the Penn State Extraterrestrial Intelligence Center, a research group dedicated to advancing SETI through the search for technosignatures. In a recent paper, they explain how future SETI efforts should consider looking for extraterrestrial technology in our Solar System.
The field of extrasolar planet studies continues to grow by leaps and bounds. Currently, 5,090 exoplanets have been confirmed in 3,816 systems, and another 8,933 candidates are awaiting confirmation. The majority of these have been Neptune-like gas giants (1,779), gas giants comparable to Jupiter or Saturn (1,536), and rocky planets many times the size of Earth (1,582). The most effective means for finding exoplanets has been the Transit Method (aka. Transit Photometry), where periodic dips in a star’s brightness are seen as an indication of a planet passing in front of its star (transiting) relative to the observer.
Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has discovered a three-planet system orbiting a Sun-like star (HD 22946, or TOI 11) located about 205.5 light-years. Based on size estimates yielded from their transits, the team theorizes that these exoplanets consist of a rocky planet several times the size of Earth (a Super-Earth) and two gas giants smaller than Neptune. Given its proximity, this system could be ideal for follow-up studies and characterization with the James Webb Space Telescope (JWST).
Be sure to observe Jupiter this week, during its finest apparition of a lifetime.
You’ve never seen Jove like this. Jupiter opposition season for 2022 is upon us tonight, as the King of the Planet shines rising in the east opposite to the setting Sun in the west. This is the very best time to catch Jupiter and its retinue of moons, as they dominate the sky throughout the night. And although Jupiter reaches opposition as seen from the Earth nearly every year, this one is special as it’s the closest to the Earth in our lifetimes, and the nearest for the 21st century.
On September 26th, NASA’s Double-Asteroid Redirect Test (DART) will rendezvous with the Near-Earth Asteroid (NEA) Didymos. By 01:14 UTC (07:14 PM EDT; 04:14 PM PDT), this spacecraft will collide with the small moonlet orbiting the asteroid (Dimorphos) to test the “kinetic impactor” method of planetary defense. This method involves a spacecraft striking an asteroid to alter its orbit and divert it from a trajectory that would cause it to collide with Earth. The event will be broadcast live worldwide and feature data streams from the DART during its final 12 hours before it strikes its target.
The James Webb Space Telescope (JWST) is the most complex and sophisticated observatory ever deployed. Using its advanced suite of infrared instruments, coronographs, and spectrometers – contributed by NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA) – this observatory will spend the next ten to twenty years building on the achievements of its predecessor, the venerable Hubble. This includes exoplanet characterization, star and planet formation, and the formation and evolution of the earliest galaxies in the Universe.
However, one of the main objectives of the JWST is to study the planets, moons, asteroids, comets, and other celestial bodies here in the Solar System. This includes Mars, the first Solar planet to get the James Webb treatment! The images Webb took (recently released by the ESA) provide a unique perspective on Mars, showing what the planet looks like in infrared wavelengths. The data yielded by these images could provide new insight into Mars’ atmosphere and environment, complimenting decades of observations by orbiters, landers, rovers, and other telescopes.
In 1916, Karl Schwarzchild theorized the existence of black holes as a resolution to Einstein’s field equations for his Theory of General Relativity. By the mid-20th century, astronomers began detecting black holes for the first time using indirect methods, which consisted of observing their effects on surrounding objects and space. Since the 1980s, scientists have studied supermassive black holes (SMBHs), which reside at the center of most massive galaxies in the Universe. And by April 2019, the Event Horizon Telescope (EHT) collaboration released the first image ever taken of an SMBH.
These observations are an opportunity to test the laws of physics under the most extreme conditions and offer insights into the forces that shaped the Universe. According to a recent study, an international research team relied on data from the ESA’s Gaia Observatoryto observe a Sun-like star with strange orbital characteristics. Due to the nature of its orbit, the team concluded that it must be part of a black hole binary system. This makes it the nearest black hole to our Solar System and implies the existence of a sizable population of dormant black holes in our galaxy.
Ever since robotic explorers began visiting the Red Planet during the 1960s and 70s, scientists have puzzled over Mars’ surface features. These included flow channels, valleys, lakebeds, and deltas that appear to have formed in the presence of water. Since then, dozens of missions have been sent to Mars to explore its atmosphere, surface, and climate to learn more about its warmer, wetter past. In particular, scientists want to know how long water flowed on the surface of Mars and whether it was persistent or periodic in nature.
The ultimate purpose here is to determine whether rivers, streams, and standing bodies of water existed long enough for life to emerge. So far, missions like Curiosityand Perseverancehave gathered volumes of evidence that show how hundreds of large lakebeds once dotted the Martian landscape. But according to a new study by an international team of researchers, our current estimates of Mars’ surface water may be a dramatic understatement. Based on a meta-analysis of years’ worth of satellite data, the team argues that ancient lakes may have once been a very common feature on Mars.
On July 12th, 2022, NASA released the first images acquired by the James Webb Space Telescope, which were taken during its first six months of operation. Among its many scientific objectives, Webb will search for smaller, rocky planets that orbit closer to their suns – especially dimmer M-type (red dwarf) stars, the most common in the Universe. This will help astronomers complete the census of exoplanets and gain a better understanding of the types of worlds that exist out there. In particular, astronomers are curious about how many terrestrial planets in our galaxy are actually “water worlds.”
These are rocky planets that are larger than Earth but have a lower density, which suggests that volatiles like water make up a significant amount (up to half) of their mass-fraction. According to a recent study by researchers from the University of Chicago and the Instituto de Astrofísica de Canarias (IAC), water worlds may be just as common as “Earth-like” rocky planets. These findings bolster the case for exoplanets that are similar to icy moons in the Solar System (like Europa) and could have significant implications for future exoplanet studies and the search for life in our Universe.