Exoplanets

This artist’s conception illustrates a Jupiter-like planet alone in the dark of space, floating freely without a parent star. 这幅艺术家的构思图说明了一颗类似木星的行星在黑暗的太空中独自游荡，没有母星。 Exoplanet hunters have found thousands of planets, most orbiting close to their host stars, but relatively few alien worlds have been detected that float freely through the galaxy as so-called rogue planets, not bound to any star. Many astronomers believe that these planets are more common than we know, but that our planet-finding techniques haven’t been up to the task of locating them. 系外行星猎人已经发现了数以千计的行星，大多数都在靠近其母星的轨道上运行，但相对而言，很少有外星世界被发现，它们作为所谓的流氓行星在星系中自由漂浮，不受任何恒星的约束。许多天文学家认为，这些行星比我们所知道的更常见，但我们的行星寻找技术还没有完成定位它们的任务。 A planet survey, called the Microlensing Observations in Astrophysics (MOA), scanned the central bulge of our Milky Way galaxy from 2006 to 2007. It used a 5.9-foot (1.8-meter) telescope at Mount John University Observatory in New Zealand, and a technique called…

Planet TOI-1231 b orbits a red dwarf star some 90 light-years away from Earth and is oddly reminiscent of our own Neptune ­– that is, a gaseous world with a potentially rich atmosphere, ripe for study. The planet is more than 3 ½ times as big around as Earth and warm by Earthly standards at 134 degrees Fahrenheit (57 Celsius). But astronomers say it is one of the “coolest,” comparatively small planets known to date, and in a prime position for the components of its atmosphere to be teased apart by space telescopes. Red dwarf stars are smaller but longer lived than our own Sun – with a year, once around the star, that is 24 days long. But the planet stays relatively cool despite…

May the Fourth Be With You! When the first Star Wars movie was released in 1977, it featured the now-iconic two-sun, “circumbinary” planet Tatooine. At that time astronomers didn’t really know if such solar systems existed. Indeed, the first extra-solar planet wasn’t detected until the early 1990s. And, the first actual circumbinary planet was detected in 2005, and it was a Jupiter-size planet orbiting a system composed of a sun-like star and a brown dwarf. Fast forward a few decades and researchers working with data from the Transiting Exoplanet Survey Satellite (TESS) discovered the mission’s first circumbinary planet, a world orbiting two stars, as shown in this image from January 2020. The planet, called TOI 1338 b, is around 6.9 times larger than Earth, or…

This artist’s concept is of a Jupiter-mass planet orbiting the nearby star Epsilon Eridani. Located 10.5 light-years away, it was the closest known exoplanet to our solar system when it was discovered in 2007. The planet is in an elliptical orbit that carries it as close to the star as Earth is from the Sun, and as far from the star as Jupiter is from the Sun. Epsilon Eridandi is a young star, only 800 million years old. It is still surrounded by a disk of dust that extends 20 billion miles from the star. The disk appears as a linear sheet of reflecting dust in this view because it is seen edge-on from the planet’s orbit, which is in the same plane as the…

Kepler-22b is the first planet discovered inside the habitable zone of a Sun-like star. This artist’s conception from 2011, shows the first planet that NASA’s Kepler mission has confirmed to orbit the region around a star where liquid water, a requirement for life on Earth, could exist. This exoplanet is 2.4 times the size of Earth, making it the smallest yet found to orbit in the middle of the habitable zone of a star like our Sun. At the time scientists did not know if the planet has a predominantly rocky, gaseous or liquid composition. It’s possible that the world would have clouds in its atmosphere, as depicted here in the artist’s interpretation. Image Credit: NASA/Ames/JPL-Caltech 开普勒-22b是在类太阳恒星的宜居带内发现的第一颗行星。这是2011年的艺术家构想，显示了NASA开普勒任务确认的第一颗行星，该行星围绕一颗恒星运行，那里可能存在液态水，而液态水是地球上生命存在的必要条件。这颗系外行星的大小是地球的2.4倍，是迄今为止发现的在像太阳这样的恒星的宜居带中间运行的最小的行星。 当时，科学家们还不知道这颗行星的主要成分是岩石、气体还是液体。这个世界的大气中可能有云，正如艺术家在这里所描述的那样。 图片来源：NASA/Ames/JPL-Caltech