If you’re a fan of the Search for Extraterrestrial Intelligence (SETI) and the Fermi Paradox, then it’s likely you’ve heard of a concept known as the Great Filter. In brief, it states that life in the Universe may be doomed to extinction, either as a result of cataclysmic events or due to circumstances of its own making (i.e., nuclear war, climate change, etc.) In recent years, it has been the subject of a lot of talk and speculation, and not just in academic circles.
Stephen Hawking and Elon Musk have also weighed in on the issue, claiming that humanity’s only chance at long-term survival is to become “interplanetary.” Addressing this very possibility, a research team led by NASA’s Jet Propulsion Laboratory (JPL) recently created a timeline for potential human expansion beyond Earth. According to their findings, we have the potential of going interplanetary by the end of the century and intragalactic by the end of the 24th!
Proxima b, the closest exoplanet to our Solar System, has been a focal point of scientific study since it was first confirmed (in 2016). This terrestrial planet (aka. rocky) orbits Proxima Centauri, an M-type (red dwarf) star located 4.2 light-years beyond our Solar System – and is a part of the Alpha Centauri system. In addition to its proximity and rocky composition, it is also located within its parent star’s habitable zone (HZ).
Until a mission can be sent to this planet (such as Breakthrough Starshot), astrobiologists are forced to postulate about the possibility that life could exist there. Unfortunately, an international campaign that monitored Proxima Centauri for months using nine space- and ground-based telescopes recently spotted an extreme flare coming from the star, one which would have rendered Proxima b uninhabitable.
On October 19th, 2017, astronomers from the Haleakala Observatory in Hawaii announced the first-ever detection of an interstellar object in our Solar System. In honor of the observatory that first spotted it, this object (designated 1I/2017 U1) was officially named ‘Oumuamua by the IAU – a Hawaiian term loosely translated as “Scout” (or, “a messenger from afar arriving first.”)
Having spent the past few years presenting this controversial theory before the scientific and astronomical community, Prof. Loeb has since shared the story of how he came to it in his new book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. The book is a seminal read, addresses the mystery of ‘Oumuamua, and (most importantly) urges readers to take seriously the possibility that an extraterrestrial encounter took place
Astronomers using a new technique may have not only found a super-Earth at a neighbouring star, but they may also have directly imaged it. And it could be nice and cozy in the habitable zone around Alpha Centauri.
However, the scientific community has since announced that the signal is unlikely to be anything other than the result of natural phenomena. This was also the conclusion reached by Amir Siraj and Prof. Abraham Loeb of Harvard University after they conducted a probability assessment on BLC1. Like the vast majority of candidate radio signals discovered to date, this one appears to be just the forces of nature saying hello.
There’s a powerful scene in the movie “Contact” (one of my favs) where lead character Ellie Arroway is sitting among an array of telescopes and hears the first alien signal – an ominous pulse – received by humanity. She races back to the control center where the array is pointed off target and then back to verify the signal. Contact is made. Shortly after, a message is found in the signal and we’ve confirmed the existence of alien life!
Ellie Arroway was inspired by a real-life pillar of the SETI community, Dr. Jill Tarter. I had the privilege of interviewing Jill Tarter last year and asked about that scene. She laughed saying “There’s not a lot of sitting around with headphones on. It’s not really that simple.” When it comes to analyzing signals from the stars for alien life, distinguishing a potential alien message from the noise of our own planet is quite complicated.
Excitingly, we’re watching that analysis play out right now as a signal which appears to originate from our closest neighbour star, Proxima Centauri, was recently detected by the Breakthrough Listen Project
In July of 2015, the New Horizonsspacecraft made history when it became the first robotic explorer to conduct a flyby of Pluto. This was followed by another first, when the NASA mission conducted the first flyby of a Kuiper Belt Object (KBO) on December 31st, 2018 – which has since been named Arrokoth. Now, on the edge of the Solar System, New Horizons is still yielding some groundbreaking views of the cosmos.
For example, we here on Earth are used to thinking that the positions of the stars are “fixed”. In a sense, they are, since their positions and motions are relatively uniform when seen from our perspective. But a recent experiment conducted by the New Horizons team shows how familiar stars like Proxima Centauri and Wolf 359 (two of the closest stars in our neighbors) look different when viewed from the edge of the Solar System.
Our closest stellar neighbour is Proxima Centauri, a small red dwarf star about 4.2 light years away from us. It’s the third member of the Alpha Centauri group, and even though it’s so close, it can’t be seen with the naked eye. In 2016 astronomers discovered a planet orbiting Proxima Centuari, named Proxima Centauri b. That planet was confirmed only a few days ago.
Now, astronomers have confirmed the existence of a second planet, Proxima Centauri c.
The closest star to the Sun is a small red dwarf star known as Proxima Centauri. It is only 4.2 light-years away and is now known to have an Earth-sized planet in its habitable zone. That doesn’t mean there is life orbiting the nearest star, but its proximity should help us understand the possibilities.
In 2016, astronomers working for the European Southern Observatory (ESO) confirmed the existence of a terrestrial planet around Earth’s closest stellar neighbor – Proxima Centauri. The discovery of this nearby extrasolar planet (Proxima b) caused no shortage of excitement because, in addition to being similar in size to Earth, it was found to orbit within the star’s habitable zone (HZ).
Thanks to an INAF-led team, a second exoplanet (a super-Earth) was found early this year around Proxima Centauri using the Radial Velocity Method. Based on the separation between the two planets, another INAF-led team attempted to observe this planet using the Direct Imaging Method. While not entirely successful, their observations raise the possibility that this planet has a system of rings around it, much like Saturn.