The ESA’s Gaia Observatory continues its astrometry mission, which consists of measuring the positions, distances, and motions of stars (and the positions of orbiting exoplanets) with unprecedented precision. Launched in 2013 and with a five-year nominal mission (2014-2019), the mission is expected to remain in operation until 2025. Once complete, the mission data will be used to create the most detailed 3D space catalog ever, totaling more than 1 billion astronomical objects – including stars, planets, comets, asteroids, and quasars.
Another benefit of this data, according to a team of researchers led by the Chinese Academy of Sciences (CAS), is the ability to predict future microlensing events. Similar to gravitational lensing, this phenomenon occurs when light from background sources is deflected and amplified by foreground objects. Using information from Gaia‘s third data release (DR3), the team predicted 4500 microlensing events, 1664 of which are unlike any we have seen. These events will allow astronomers to conduct lucrative research into distant star systems, exoplanets, and other celestial objects.
When the Universe erupted into existence with the Big Bang, all of its matter was compressed into a tiny area. Cosmologists theorize that in some regions, subatomic matter may have been so tightly packed that matter collapsed into primordial black holes. If these primordial black holes exist, they’re small, and they could be hiding among the population of free-floating planets.
At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change. Periodically, planets are kicked out of their star systems to become “rogue planets,” bodies that are no longer gravitationally bound to any star and are adrift in the interstellar medium (ISM). Some of these planets may be gas giants with tightly bound icy moons orbiting them, which they could bring with them into the ISM.
Like Jupiter, Saturn, Uranus, and Neptune, these satellites could have warm water interiors that might support life. Other research has indicated that rocky planets with plenty of water on their surfaces could also support life through a combination of geological activity and the decay of radionuclides. According to a recent paper by an international team of astronomers, there could be hundreds of rogue planets in our cosmic neighborhood. Based on their first-ever feasibility analysis, they also indicate that deep space missions could explore these unbound objects more easily than planets still bound to their stars.
A pair of new studies set to be published in The Astronomical Journal examine new discoveries in the field of rogue planets, which are free-floating exoplanets that drift through space unbound by the gravitational tug of a star. They can form within their own solar system and get ejected, or they can form independently, as well. The first study examines only the second discovery of an Earth-mass rogue planet—the first being discovered in September 2020—while the second study examines the potential number of rogue planets that could exist in our Milky Way Galaxy.
Scientists have found what appear to be rogue planets hidden in old survey data. Their results are starting to define the poorly-understood rogue planet population. In the near future, the Nancy Grace Roman Space Telescope will conduct a search for more free-floating planets, and the team of researchers developed some methods that will aid that search.
Earlier this year, astronomers used microlensing and the Hubble Space Telescope to detect, for the first time, a rogue black hole that is about 5,000 lightyears away from Earth. Now, with more precise measurements, they have been able to determine an approximate mass of this hard-to-detect object. However, the surprisingly low mass means there’s a chance this object may not actually be a black hole.
NASA’s Kepler planet-hunting spacecraft was deactivated in November 2018, about ten years after it launched. The mission detected over 5,000 candidate exoplanets and 2,662 confirmed exoplanets using the transit method. But scientists are still working with all of Kepler’s data, hoping to uncover more planets in the observations.
A team of researchers have announced the discovery of one more planet in the Kepler data, and this one is nearly a twin of Jupiter.
In the past we’ve reported about how the Roman Space Telescope is going to potentially be able to detect hundreds of thousands of exoplanets using a technique known as “microlensing”. Exoplanets won’t be the only things it can find with this technique though – it should be able to find solitary black holes as well.
Recently we reported on a haul of 2,200 new exoplanets from the 2 year primary mission of the Transiting Exoplanet Survey Satellite (TESS). But that is just the tip of the iceberg in terms of exoplanet hunting. If calculations from NASA are correct the Nancy Grace Roman Space Telescope could detect up to 100,000 new exoplanets when it launches in 2025.