How common is Earth?
Stars are born when huge clouds of dust and gas collapse in on themselves and ignite. These clouds are made up of raw elements, like oxygen and titanium, and each cloud has a unique composition that imprints on the star. And within the stellar afterbirth – from the material that didn’t find its way into the star – planets are formed.
In the past few decades, there has been an explosion in the number of planets discovered beyond our Solar System. With over 4,000 confirmed exoplanets to date, the process has gradually shifted from discovery towards characterization. This consists of using refined techniques to determine just how likely a planet is to be habitable.
Alpha Centauri is the closest star system to us, at 4.37 light-years (about 25 trillion miles) away. In 2016, astronomers discovered an exoplanet orbiting one of the three stars in the Alpha Centauri system. Spurred on by that discovery, the European Southern Observatory (ESO) has developed a new instrument to find any other planets that might be in the Alpha Centauri system, and it’s busy looking right now.
In August of 2016, astronomers from the European Southern Observatory (ESO) announced the discovery of an exoplanet in the neighboring system of Proxima Centauri. The news was greeted with consider excitement, as this was the closest rocky planet to our Solar System that also orbited within its star’s habitable zone. Since then, multiple studies have been conducted to determine if this planet could actually support life.
If it weren’t for the sun constantly showering us with energy, there would be no life on Earth. But eventually stars like it run out of fuel, expand into red giants and finally collapse into small, faint objects called white dwarfs. So what will happen to us and the other planets in our solar system when the sun dies? It’s not been entirely clear.
Looking to the future, NASA and other space agencies have high hopes for the field of extra-solar planet research. In the past decade, the number of known exoplanets has reached just shy of 4000, and many more are expected to be found once next-generations telescopes are put into service. And with so many exoplanets to study, research goals have slowly shifted away from the process of discovery and towards characterization.
This newly-confirmed exoplanet is a massive hot Jupiter that whips around its star every 3.85 days. From the surface, the star would appear 60 times larger in diameter than the Sun as seen from Earth.
Though concentric rings — shown here in particularly beautiful clarity — are a common substructure among such discs, their widths, separations, and number can vary greatly. It’s still unclear how these substructures form, and how planets emerge from them. Quantifying and studying these similarities and differences was a motivator for constructing ALMA, and was the main objective of DSHARP. These details may hold clues to the type of planetary system that will eventually emerge.