Skip to main content
  1. Home
  2. Space
  3. News

Hubble spots a wacky exoplanet with yellow skies and iron rain

Georgina Torbet
By

Astronomers have spotted an utterly bizarre exoplanet using data from the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite (TESS), and the Magellan observatory. WASP-79b, located 780 light-years away, has skies which would look yellow during the day.

The sky on Earth appears blue due to a phenomenon called Rayleigh scattering, in which tiny particles in the atmosphere filter out certain wavelengths of light. The shorter (blue) wavelengths of light are scattered more than longer (red) wavelengths, which is why the sky appears blue.

Recommended Videos

But there’s something odd going on on planet WASP-79b, because it doesn’t seem to show Rayleigh scattering in the way that scientists expected. When studying the planet using a spectrograph, which measures light wavelengths to determine chemical compositions, the scientists expected to see a decrease in the amount of blue starlight. But instead, they saw the opposite — the blue light wavelengths were less scattered by the atmosphere.

Related

“This is a strong indication of an unknown atmospheric process that we’re just not accounting for in our physical models,'” Kristin Showalter Sotzen of the Johns Hopkins University Applied Physics Laboratory said in a statement. “I’ve shown the WASP-79b spectrum to a number of colleagues, and their consensus is ‘that’s weird’.”

An artist's illustration of the super-hot exoplanet WASP-79b
An artist’s illustration of the super-hot exoplanet WASP-79b, located 780 light-years away. NASA, ESA, and L. Hustak (STScI)

That means that the planet would have a yellow-colored sky during the day, and the researchers have no idea why. “Because this is the first time we’ve see this, we’re really not sure what the cause is,” Sotzen said.

“We need to keep an eye out for other planets like this because it could be indicative of unknown atmospheric processes that we don’t currently understand. Because we only have one planet as an example we don’t know if it’s an atmospheric phenomenon linked to the evolution of the planet.”

And the skies aren’t the only extreme thing about this planet. As a “hot Jupiter,” the planet orbits extremely close to its star, completing an orbit in just three and a half Earth days. That means its atmosphere is phenomenally hot, reaching up to 3,000 degrees Fahrenheit, which is hot enough to cause molten iron to rain down onto the surface from manganese sulfide or silicate clouds.

As well as being a quirky object of interest, astronomers think that studying this planet could help them learn about how planets form, because it has an unusual polar orbit around its star which brings into question theories about how hot Jupiters develop. It will be one of the first targets of study for NASA’s upcoming James Webb Space Telescope.

Editors' Recommendations

Topics
Georgina Torbet
Georgina Torbet
Space Writer
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble spots a massive star forming amid clouds of dust and gas
This image from the NASA/ESA Hubble Space Telescope is a relatively close star-forming region known as IRAS 16562-3959.

A stunning new image from the Hubble Space Telescope shows the birth of a new, massive star at around 30 times the mass of our sun. Nestled with a nearby star-forming region called IRAS 16562-3959, the baby star is located within our galaxy and around 5,900 light-years from Earth.

You can see the sparkle of bright stars throughout the image, with the star-forming region visible as the orange-colored clouds of dust and gas stretching diagonally across the frame. These clouds are where dust and gas clump together to form knots, gradually attracting more dust and gas, growing over time to become protostars.

Read more
James Webb photographs two potential exoplanets orbiting white dwarfs
Illustration of a cloudy exoplanet and a disk of debris orbiting a white dwarf star.

Even though scientists have now discovered more than 5,000 exoplanets, or planets outside our solar system, it's a rare thing that any telescope can take an image of one of these planets. That's because they are so small and dim compared to the stars that they orbit around that it's easier to detect their presence based on their effects on the star rather than them being detected directly.

However, thanks to its exceptional sensitivity, the James Webb Space Telescope was recently able to image two potential exoplanets orbiting around small, cold cores of dead stars called white dwarfs directly.

Read more
Hubble spies baby stars being born amid chaos of interacting galaxies
Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. They form when knots of gas gravitationally collapse to create about 1 million newborn stars per cluster.

When two galaxies collide, the results can be destructive, with one of the galaxies ending up ripped apart, but it can also be constructive too. In the swirling masses of gas and dust pulled around by the gravitational forces of interacting galaxies, there can be bursts of star formation, creating new generations of stars. The Hubble Space Telescope recently captured one such hotbed of star formation in galaxy AM 1054-325, which has been distorted into an unusual shape due to the gravitational tugging of a nearby galaxy.

Galaxy AM 1054-325 has been distorted into an S-shape from a normal pancake-like spiral shape by the gravitational pull of a neighboring galaxy, as seen in this Hubble Space Telescope image. A consequence of this is that newborn clusters of stars form along a stretched-out tidal tail for thousands of light-years, resembling a string of pearls. NASA, ESA, STScI, Jayanne English (University of Manitoba)

Read more