Exoplanet HD 189733b Weather Forecast: Super Windy — As In, 5,400 MPH Winds

Exoplanet HD 189733b is rather unique among exoplanets (that is, planets beyond the Solar System) that have been discovered so far: it has an atmosphere. An atmosphere that produces winds of up to 5,400 miles per hour.

As DB Techno reports, scientists discovered the lovingly-named Exoplanet HD 189733b in 2005. They found it in the same way they’ve found almost all other exoplanets — they observed its “transit” — that is, its passage between its sun and observers on the ground. In the photo below, you can see what’s known as the Transit of Venus, where Venus passes between the Sun and observers on the ground. Exoplanet HD 189733b was discovered the same way — only with significantly more powerful telescopes, and teams of scientists using specialized equipment.

Venus moves across the face of the sun - its "Transition." Exoplanet x was discovered the same way. [Image By NASA/SDO, AIA (https://flic.kr/p/cbYeYU) [Public domain], via Wikimedia Commons]

Located some 63 light years away, in the constellation Vulpecula, Exoplanet HD 189733b is a case study in extremes. It has a mass 13 percent higher than that of Jupiter, but unlike Jupiter, it orbits perilously close to its star (its “year” is only 2.2 Earth days) at a “breakneck” speed of about 341,000 miles per hour. Because it’s comparable in size to Jupiter, but is hot — scientists estimate its surface temperature is 3,700 degrees Fahrenheit (by comparison, the surface temperature of Venus is 864 degrees Fahrenheit, according to Space) — scientists refer to such exoplanets as a “hot Jupiter.”

These conditions made the new exoplanet a target of special interest for scientists, says lead researcher Tom Louden, of the University of Warwick.

“HD 189733b’s velocity was measured using high resolution spectroscopy of the Sodium absorption featured in its atmosphere. As parts of HD 189733b’s atmosphere move towards or away from the Earth the Doppler effect changes the wavelength of this feature, which allows the velocity to be measured.”

This marks the first time an exoplanet’s atmosphere has been extensively studied.

“The surface of the star is brighter at the center than it is at the edge, so as the planet moves in front of the star the relative amount of light blocked by different parts of the atmosphere changes. For the first time we’ve used this information to measure the velocities on opposite sides of the planet independently, which gives us our velocity map.”

And those velocity maps revealed something rather startling: the exoplanet’s atmosphere produces winds of up to 5,400 miles per hour, according to Tech Times. That is 20 times higher than the highest wind speed ever recorded on Earth (253 miles per hour, during an Australian hurricane). 5,400 mph winds would completely level New York City.

Thousands of exoplanets have been discovered in the past two decades, according to an August, 2015, Space report. Some, like our own Jupiter and Saturn, are mostly gas; others, like our own Mars or Venus, are rocky; others are mostly ice. Scientists are studying them in the hopes of finding something that has, so far, been elusive in our own Solar System: life.

In order for life to exist on an exoplanet, it has to be in what’s called the “habitable zone” — that is, not too close to its star to make it too hot to support too life, or too far away to be too cold. A handful of such exoplanets have, in fact, been found in habitable zones, but it may be impossible to prove if life exists on those planets, due to their distance away from Earth.

One thing that is certain, however, is that Exoplanet HD 189733b, with its nearly 4,000-degree surface temperature and 5,400 mph winds, does not support life — at least, not life as we know it.

[Image via Shutterstock / muratart]