When the interstellar object (ISO) Oumuamua appeared in our Solar System in 2017, it generated a ton of interest. The urge to learn more about it was fierce, but unfortunately, there was no way to really do so. It came and went, and we were left to ponder what it was made of and where it came from. Then, in 2019, the ISO comet Borisov came for a brief visit, and again, we were left to wonder about it.
There’s bound to be more of these ISOs traversing our Solar System. There’s been talk of having missions ready to go to visit one of these interstellar visitors in the future, but for that to happen, we need advance notice of its arrival. Could the Vera Rubin Observatory tell us far enough in advance?
In the coming years, NASA plans to send several astrobiology missions to Venus and Mars to search for evidence of extraterrestrial life. These will occur alongside crewed missions to the Moon (for the first time since the Apollo Era) and the first crewed missions to Mars. Beyond the inner Solar System, there are ambitious plans to send robotic missions to Europa, Titan, and other “Ocean Worlds” that could host exotic life. To accomplish these objectives, NASA is investing in some interesting new technologies through the NASA Innovative Advanced Concepts (NIAC) program.
This year’s selection includes solar-powered aircraft, bioreactors, lightsails, hibernation technology, astrobiology experiments, and nuclear propulsion technology. This includes a concept for a Thin Film Isotope Nuclear Engine Rocket (TFINER), a proposal by senior technical staff member James Bickford and his colleagues at the Charles Stark Draper Laboratory – a Massachusetts-based independent technology developer. This proposal relies on the decay of radioactive isotopes to generate propulsion and was recently selected by the NIAC for Phase I development.
Astronomers have discovered two known interstellar objects (ISO), ‘Oumuamua and 21/Borisov. But there could be thousands of these objects passing through the Solar System at any time. According to a new paper, the upcoming Vera Rubin Telescope will be a fantastic interstellar object hunter, and could possibly find up to 70 objects a year coming from other star systems.
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.
Here’s a thorny problem: What if life doesn’t always appear on planets that can support it? What if we find more and more exoplanets and determine that some of them are habitable? What if we also determine that life hasn’t appeared on them yet?
Could we send life-bringing comets to those planets and seed them with terrestrial life? And if we could do that, should we?
We finally have the technological means to detect interstellar objects. We’ve detected two in the last few years, ‘Oumuamua and 2I/Borisov, and there are undoubtedly more out there. As such, there’s been a lot of interest in developing a mission that could visit one once we detect it. But what would such a mission look like? Now, a draft paper from a team of primarily American scientists has taken a stab at answering that question and moved us one step closer to launching such a mission.
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.
Do aliens exist? Almost certainly. The universe is vast and ancient, and our corner of it is not particularly special. If life emerged here, it probably did elsewhere. Keep in mind this is a super broad assumption. A single instance of fossilized archaebacteria-like organisms five superclusters away would be all it takes to say, “Yes, there are aliens!” …if we could find them somehow.
In a recent study submitted to Earth and Planetary Astrophysics, a team of researchers from Yale University investigated how to identify impact craters that may have been created by Interstellar Objects (ISOs). This study is intriguing as the examination of ISOs has gained notable interest throughout the scientific community since the discoveries and subsequent research of ‘Oumuamua and Comet 2I/Borisov in 2017 and 2019, respectively. In their paper, the Yale researchers discussed how the volume of impact melt within fixed-diameter craters could be a possible pathway for recognizing ISO craters, as higher velocity impacts produce greater volumes of impact melt.
Back in 2014, an object crashed into the ocean just off the coast of Papua New Guinea. Data collected at the time indicated that the meteorite just might be an interstellar object, and if that’s true, then it’s only the third such object known (after Oumuamua and Borisov), and the first known to exist on Earth. Launching an undersea expedition to find it would be a long shot, but the scientific payoff could be enormous.