A newly found planet could melt lead and many other tough elements in its atmosphere as it whips around its hot parent star every 24 hours. So to say the least, it isnât a spot where life would ever want to exist. But studying LTT 9779b is still an intriguing laboratory to help us look for life elsewhere, researchers said.
“For the first time, we measured the light coming from this planet that shouldn’t exist,” said study lead author Ian Crossfield, a physics and astronomer researcher at Kansas University, in a statement. “This planet is so intensely irradiated by its star that its temperature is over 3,000 degrees Fahrenheit and its atmosphere could have evaporated entirely. Yet, our Spitzer [Space Telescope] observations show us its atmosphere via the infrared light the planet emits.”
Astronomers spotted the planet using NASAâs Transiting Exoplanet Survey Satellite (TESS), whose goal is to find Earth-like planets close to home. But TESS is seeing all kinds of weird worlds as it peers at the light signals from stars, which dip as planets move across their parent stars from Earthâs perspective. Bigger planets produce a stronger dip due to the planetsâ sheer size, just like the Neptune-sized LTT 9779b. The new study used NASAâs Spitzer observatory for follow-up observations.
Ironically, this world appears strangely cool despite the proximity to its star. “The planet is much cooler than we expected, which suggests that it is reflecting away much of the incident starlight that hits it, presumably due to dayside clouds,” said co-author and exoplanet researcher Nicolas Cowan at McGill University in Montreal, in the same statement.
The ‘hot Neptune’ planet has a different emission spectrum from many larger ‘hot Jupiters’ studied over the past few decades, but what is going on in the atmosphere still needs more study. Companion papers to this study looked at aspects such as the composition of the atmosphere (a study technique that could be applied to more life-friendly planets in the future) and analyses of the atmosphere during eclipses. The eclipses make it easier to separate the signal of the planetâs atmosphere from the signal of the star, although higher resolution would be ideal.
Crossfield said searching for oxygen signals on a huge world like LTT 9779b is a lot easier than looking for smaller, more subtle signals on a planet closer to Earthâs size. By doing the easy stuff first, this will make the search for life a little more efficient in the future.
“If anyone is going to believe what astronomers say about finding signs of life or oxygen on other worlds, we’re going to have to show we can actually do it right on the easy stuff first,” he said. “In that sense these bigger, hotter planets like LTT 9779b act like training wheels and show that we actually know what we’re doing and can get everything right.”
And more resolution will be coming to astronomers shortly. NASA hopes to launch its long-delayed James Webb Space Telescope sometime in 2021, which will be able to peer at planets with unprecedented high resolution. JWST isnât exactly optimized for looking at tiny Earth-like planets, but the studies it performs will lay the groundwork for even more powerful telescopes in the 2030s and beyond.
I’ve been writing about space exploration since 2004. I began full-time freelancing about this topic in September 2012, after working as a business reporter, copy editor
I’ve been writing about space exploration since 2004. I began full-time freelancing about this topic in September 2012, after working as a business reporter, copy editor and web reporter at various publications. My work covers all aspects of space — exploration, astronomy, basic science and more — and I’ve been published in trade magazines and news outlets across Canada and the U.S. Follow me on Twitter — @howellspace.
Atmosphere, Exoplanet, Star, Astronomy, Transiting Exoplanet Survey Satellite, Earth, Hot Jupiter
World news – CA – Super-Hot Planet âShouldnât Existâ, And Yet It Persists