To date, astronomers have confirmed 5,272 exoplanets in 3,943 systems using a variety of detection methods. Of these, 1,834 are Neptune-like, 1,636 are gas giants (Jupiter-sized or larger), 1,602 are rocky planets several times the size and mass of Earth (Super-Earths), and 195 have been Earth-like. With so many exoplanets available for study (and next-generation instruments optimized for the task), the process is shifting from discovery to characterization. And discoveries, which are happening regularly, are providing teasers of what astronomers will likely see in the near future.
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The hunt for habitable extrasolar planets continues! Thanks to dedicated missions like Kepler, TESS, and Hubble, the number of confirmed extrasolar planets has exploded in the past fifteen years (with 5,272 confirmed and counting!). At the same time, next-generation telescopes, spectrometers, and advanced imaging techniques are allowing astronomers to study exoplanet atmospheres more closely. In short, the field is shifting from the process of discovery to characterization, allowing astronomers to more tightly constraint habitability.
Jupiter’s second Galilean moon, Europa, is one of the most fascinating planetary objects in our Solar System with its massive subsurface ocean that’s hypothesized to contain almost three times the volume of water as the entire Earth, which opens the possibility for life to potentially exist on this small moon. But while Europa’s interior ocean could potentially be habitable for life, its unique surface features equally draw intrigue from scientists, specifically the large red streaks that crisscross its cracked surface.
About 50,000 years ago, a nickel-iron meteorite some 50 meters across plowed into the Pleistocene-era grasslands of what is now Northern Arizona. It was traveling fast—about 13 kilometers per second. In just a few seconds, an impact dug out a crater just over a kilometer wide and spread rocks from the site for miles around.
An astronaut’s gotta eat, right? Especially if they are on a long-duration mission to places like the Moon. Scientists have been looking into how the lunar regolith could possibly support growing food for humans, as growing plants for food and oxygen will be critical for future long-term lunar missions.
The early Universe was swimming with dwarf galaxies only a few hundred million years after the Big Bang. They merged with each other over time, building larger and more massive galaxies. At the same time, the giant black holes inside these dwarfs merged, too.
On Mars, NASA’s Perseverance rover is busy collecting rock samples that will be retrieved and brought back to Earth by the Mars Sample Return (MSR) mission. This will be the first sample-return mission from Mars, allowing scientists to analyze Martian rocks directly using instruments and equipment too large and cumbersome to send to Mars. To this end, scientists want to ensure that Perseverance collects samples that satisfy two major science goals – searching for signs of life (“biosignatures”) and geologic dating.
In the first data taken last summer with the Near Infrared Camera (NIRCam) on the new James Webb Space Telescope, astronomers found six galaxies from a time when the Universe was only 3% of its current age, just 500-700 million years after the Big Bang. While its incredible JWST saw these galaxies from so long ago, the data also pose a mystery.
The Milky Way Galaxy contains an estimated one hundred billion stars. Between these lies the Interstellar Medium (ISM), a region permeated by gas and dust grains. This dust is largely composed of heavier elements, including silicate minerals, ice, carbon, and iron compounds. This dust plays a key role in the evolution of galaxies, facilitating the gravitational collapse of gas clouds to form new stars. This galactic dust is measurable by how it attenuates starlight from distant galaxies, causing it to shift from ultraviolet to far-infrared radiation.
Dust storms are a serious hazard on Mars. While smaller storms and dust devils happen regularly, larger ones happen every year (during summer in the southern hemisphere) and can cover continent-sized areas for weeks. Once every three Martian years (about five and a half Earth years), the storms can become large enough to encompass the entire planet and last up to two months. These storms play a major role in the dynamic processes that shape the surface of Mars and are sometimes visible from Earth (like the 2018 storm that ended the Opportunity rover’s mission).
Sending a lander to Venus presents several huge engineering problems. Granted, we’d get a break from the nail-biting entry, descent and landing, since Venus’ atmosphere is so thick, a lander would settle gently to the surface like a stone settles in water — no sky cranes or retrorockets required.
The two brightest planets pass less than half a degree apart at dusk during a spectacular conjunction on the night of March 1st.
On Earth, geologists study rocks to help better understand the history of our planet. In contrast, planetary geologists study meteorites to help better understand the history of our solar system. While these space rocks put on quite the spectacle when they enter our atmosphere at high speeds, they also offer insights into both the formation and evolution of the solar system and the planetary bodies that encompass it. But what happens as a meteorite traverses our thick atmosphere and lands on the Earth? Does it stay in its pristine condition for scientists to study? How quickly should we contain the meteorite before the many geological processes that make up our planet contaminate the specimen? How does this contamination affect how the meteorite is studied?
An asteroid the size of the Empire State Building flew past Earth in early February, coming within 1.8 million km (1.1 million miles) of our planet. Not only is it approximately the same size as the building, but astronomers found the asteroid – named 2011 AG5 — has an unusual shape, with about the same dimensions as the famous landmark in New York City.
Jupiter is well known for its spectacular aurorae, thanks in no small part to the Juno orbiter and recent images taken by the James Webb Space Telescope (JWST). Like Earth, these dazzling displays result from charged solar particles interacting with Jupiter’s magnetic field and atmosphere. Over the years, astronomers have also detected faint aurorae in the atmospheres of Jupiter’s largest moons (aka. the “Galilean Moons“). These are also the result of interaction, in this case, between Jupiter’s magnetic field and particles emanating from the moons’ atmospheres.
When stars die, they spread the elements they’ve created in their cores out to space. But, other objects and processes in space also create elements. Eventually, that “star stuff” scatters across the galaxy in giant debris clouds. Later on—sometimes millions of years later—it settles onto planets. What’s the missing link between element creation and deposition on some distant world?
Hard to believe, but the Perseverance Rover has begun its third year exploring Mars. On Feb. 18, 2021, Perseverance rover survived the harrowing landing at Jezero Crater, and almost immediately, began an expedition to collect a geologically diverse set of rock samples, ones that could help answer the question if Mars once had ancient microbial life.
Planet 9 continues to remain elusive. This potential super-Earth-sized object in the outer Solar System is only hypothetical, as something out there appears to be gravitationally influencing several Kuiper Belt Objects into unusual orbits. Whatever or wherever it may be, Planet 9 has yet to be found, despite several different hypotheses and numerous observational searches.
If it turns out that a future extraterrestrial invasion force is headed by a clone of George Washington, we’ll have only ourselves to blame.
Blue Origin wants to build solar panels on the Moon, out of the Moon, SpaceX sold its floating landing pads, and another asteroid hits Earth exactly where and when astronomers predicted.
The European Space Agency is working on a new mission that would act as an early warning system for dangerous, hard-to-see asteroids. Called NEOMIR (Near-Earth Object Mission in the InfraRed), the spacecraft would orbit between the Earth and the Sun at the L1 Lagrange Point, finding space rocks that otherwise get lost in the glare of the Sun.