Where we dive deep into the incredible discovery of Barnard’s Star b,the second-closest known exoplanet to Earth.This icy, dimly-lit world was discovered through data collected by a world-wide array of telescopes, including the European Southern Observatory’s planet-hunting HARPS instrument. Astronomers were able to measure the star’s wobble—the effect of the planet’s orbit on the star—with extreme precision, accounting for movements as small as 2 miles per hour. What’s more, Barnard’s Star is the fastest moving star in the night sky, travelling about 310,000 mph (500,000 kilometers) per hour in relation to our Sun, or the width of the Moon every 180 years.
The data indicate that Barnard’s Star b is likely a super Earth, with a mass at least three times that of our own planet. But due to its distance from its host star—Barnard’s Star is a red dwarf which only dimly illuminates its planet—it receives only 2% of the energy that we receive from the Sun. This means that Barnard’s Star b is likely an extremely cold world, much colder than any planet in our solar system.
This remarkable discovery opens up a whole new realm for space exploration. Red dwarfs are some of the most common stars in our galaxy and, because they are so faint and cool, they offer the best chance of finding habitable worlds. We now have concrete data on an exoplanet orbiting one such star and this could be used to refine our understanding of what conditions are necessary for a planet to be habitable.
Additionally, this discovery reinforces the notion that there are plenty of other worlds out there and highlights how far we’ve come in our ability to detect them. This news should give us hope that eventually we may be able to find a world similar to our own. Until then, we must continue to explore and uncover new information about the planets we’ve already discovered.