The ESO finds another exoplanet that's definitely not a place for us to go.
- WASP-76b is an extremely hot planet whose cooler side has a surface temperature of 1,500° C (2732° F).
- Iron that evaporates in the heat of the planet's day side rains down in molten form on the night side.
- ESO learned more about the planet's intense climate thanks to its new ESPRESSO (Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations) instrument.
A hellish place to visit<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjg4Mzg0Mi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMjYyMTEwN30.IzDV8_YkgFSyuEgK50_yVb_1nccVtsiPXawc9t9JsNA/img.jpg?width=980" id="432db" class="rm-shortcode" data-rm-shortcode-id="c9635706c46b93db9acbe024d950ec2d" data-rm-shortcode-name="rebelmouse-image" alt="concept planet rendering" />Image source: Dotted Yeti/Shutterstock<p>WASP-76b is one of the most extreme exoplanets astronomers have laid eyes on so far, and both its day and night sides are way to hot for us. It was first identified using the <a href="https://www.eso.org/public/usa/teles-instr/paranal-observatory/vlt/" target="_blank">Very Large Telescope</a> (VLT) at the European Southern Observatory (ESO) Cerro Paranal, 2,600 meters above sea level in the super-dry Atacama Desert in Chile. Recent observations of the gas giant's chemistry by the ESO VLT's <a href="https://www.eso.org/public/teles-instr/paranal-observatory/vlt/vlt-instr/espresso/" target="_blank">ESPRESSO</a> instrument revealed its bizarre extremes and iron rain. ESPRESSO is an acronym for the "Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations."</p><p>WASP-76b is "tidally locked" to its star, meaning that the same side is always facing its sun. The day side gets up to 2400° C (4352°F) while the night side maxes out at a balmy 1,500° C (2732° F).</p><p>That day side is so hot that molecules separate into atoms, and metals like iron evaporate into the blistering atmosphere. ESPRESSO's data posed an intriguing question. "The observations show," says astrophysicist María Rosa Zapatero Osorio, "that iron vapor is abundant in the atmosphere of the hot day side of WASP-76b." However, that strong iron signature at the evening boundary between the two sides of WASP-76b was nowhere to be seen near the morning edge. Where could it go? Astronomers believe that the atmospheric and rotational winds carry a fair amount of the iron vapor to the night side where it falls as molten iron rain.</p>
Because exoplanets are always so normal?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjg4Mzg1MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMDg1NDMxM30.mOjWpfNi1z2978ZrMIHCezTF1HsRnoLJXANRUgcT9Aw/img.jpg?width=980" id="0984c" class="rm-shortcode" data-rm-shortcode-id="33f5e67259e67d978b66eb4d011a2b03" data-rm-shortcode-name="rebelmouse-image" alt="concept exoplanet renderings" />
Image source: Jurik Peter/Shutterstock<p>Well, not really. While searching for Earth-like exoplanets, astronomers <a href="https://www.wired.com/2009/01/top-exoplanets/" target="_blank">keep finding a planets</a> that definitely don't qualify.</p><p>WASP-76b is way too hot, for example, but it's hardly the only orbiting inferno. Consider <a href="https://www.nasa.gov/mission_pages/spitzer/multimedia/F-Black-artist.html" target="_blank">HD 149026b</a>, whose surface temperature is just slightly cooler than WASP-76b, coming in at just over 2,000° C (3632°F).</p><p>Then there's <a href="https://www.nasa.gov/vision/universe/newworlds/Rocky_planet.html" target="_blank">OGLE-2005-BLG-390Lb</a>, a big — 5.5 times the size of Earth — rocky sphere that's so so cold: -220° C (-364°F). Brrr.</p><p><a href="https://www.nasa.gov/mission_pages/hubble/exoplanet_transit.html" target="_blank">SWEEPS-10</a> is really close to its star, just 1.2 million kilometers, and races around its sun every 10 hours, as opposed to our roughly 365 days. That proximity means that it's particularly vulnerable to eventually being pulled apart, unless it slips away. And <a href="https://en.wikipedia.org/wiki/CoKu_Tau/4" target="_blank">CoKu Tau/4</a> is just a mere babe, only a million years old. </p>
An immediate win for ESPRESSO<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjg4Mzg1Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MDIyMzA0OX0.I9qoAKfK0IK7QrapuYk1KCleIV4BzckoK5bYD2O0y_s/img.jpg?width=980" id="052b8" class="rm-shortcode" data-rm-shortcode-id="b3601585a06d5050a7ddd6f2867dd558" data-rm-shortcode-name="rebelmouse-image" />
Image source: ESO/M. Zamani/Wikimedia<p>Credit for the new, deeper understanding of WASP-76b must go to ESPRESSO, which was designed to help search for Earth-like planets around Sun-like stars. In fact, the WASP-76b insights were derived from the instrument's very first observations made in September 2018 by the scientific consortium of experts from Portugal, Italy, Switzerland, Spain and the ESO responsible for the instrument.</p><p>Insights such as these have changed the way scientists see ESPRESSO. It's not just for finding exoplanets, but also helping explain them. "We soon realized that the remarkable collecting power of the VLT and the extreme stability of ESPRESSO made it a prime machine to study exoplanet atmospheres," <a href="https://www.eso.org/public/news/eso2005/" target="_blank">says Pedro Figueira</a>, ESPRESSO instrument scientist at ESO in Chile.</p><p>Meanwhile the search for additional exoplanets continues. At the time of writing, 4,135 exoplanets <a href="https://exoplanetarchive.ipac.caltech.edu" target="_blank">have been found</a> with 55 of them considered potentially <a href="http://phl.upr.edu/projects/habitable-exoplanets-catalog" target="_blank">habitable</a> by life as we know it.</p>
She may not be ours forever.
- A new study suggests that the moons of gas-giant exoplanets may break away into their own orbits, called "ploonets."
- Planet + moon = ploonet.
- As the gas giants move inward toward their suns, the orbits of their moons are often disrupted, according to new computer models.
Image source: JPL/BigThink<p>The research in the new paper is grounded on the manner in which large gas giants have been observed to slowly move inward through their solar systems toward their respective suns. It suggests that, as such a body draws close to the star, its moon's orbit — affected at that juncture by both the gravitational pull of the planet <em>and</em> the host star — experiences an increase in energy, which becomes unstable. This, eventually, releases the moon from the gravitational bonds of its parent parent. </p><p>Further, the paper's conclusions are based on a series of computer simulations that researchers conducted regarding what would happen to a moon orbiting a migrating gas giant. What was discovered? <br></p><p>The models found that 44 percent of the moons would meet their demise by being pulled <em>into</em> their planets (this could explain some of the planetary rings that have been observed). The system's star would seize and destroy another 6 percent. Significant amount of exomoons, however, — about 48 percent of them — would split off from their planets and begin orbiting their star as "ploonets." Around 2 percent would be blown out of their solar system altogether.</p><p>This would certainly explain why we haven't definitively found any evidence of exomoons yet. <span></span></p>
A machine learning algorithm has shown it can discover planets from weak signals overlooked in the Kepler spacecraft’s database.
Humans in the Western world for a long time thought that Earth was the center of the universe. At one point, it was heresy not to think so. After the heliocentric universe was adopted, we felt smaller and less self-important. But we’d also gained something, new knowledge and a new avenue in which to explore the heavens. That was a paradigm shift in our understanding and now, it’s happening again.
Scientists release observation data from 1,600 stars in hopes the public can help find planets that orbit stars outside our solar system.