Hot Jupiters are the most astounding planets in the galaxyGeorge Dvorsky8/21/13 1:09pmFiled to: Daily explainerspaceastronomycosmologygas giantsplanetologyexometerologyhot jupitersjupiterscience375EditPromoteShare to KinjaToggle Conversation toolsGo to permalink They’re big, full of gas, and have a penchant for hanging out way too close to their parents. These “hot Jupiters” are among the most common extrasolar planets in the galaxy. Here’s what the latest science is telling us about these celestial wonders.AdvertisementTo date, astronomers have catalogued over 850 planets outside our solar system. This is incredible when you consider that just 20 years ago we had absolutely no conception of what other solar systems might look like. And in fact, prior to these discoveries, we wrongly assumed that our solar system was typical: small, rocky planets on the inside, large gas giants on the outside.But nothing could be further from the truth. Solar systems come in all sorts of crazy shapes and sizes. If anything, we’re the oddballs.Image: Artistic impression via HubbleScientists first got an inkling of this back in 1995 with the discovery of the very first exoplanet orbiting a sun-like star, 51 Pegasi b, also called Bellerophon. The astronomers were left baffled by the find: A Jupiter-like planet — but in a remarkably close orbit to its parent star. The discovery was so unexpected — and so weird — that astronomers brushed it off as a kind of celestial anomaly.Selection EffectBut then they started to find others just like it. And another. And another.AdvertisementThe Milky Way, we have learned, is littered with these things, which have since been dubbed “hot Jupiters.”As astronomers soon realized, however, these discoveries were marred by a kind of observational selection effect. Without question, they were finding so many hot Jupiters because of how they were finding them, namely the transit method of detection in which a planet is spotted when it passes directly over its parent star.