Feed aggregator

What is that light in the sky?

Pandora's Cluster of Galaxies

Blown by fast winds from a hot, massive star,

Magnificent spiral galaxy

What if you saw your shadow on Mars and it wasn't human?

Why does

Is the Lion Nebula the real ruler of the

The ESA website is a key tool to help us communicate about our activities. We want to make sure that our website meets the needs and expectations of our audience. That's why we are launching a survey to collect your feedback and suggestions on how to improve the esa.int website.

The Hubble Space Telescope’s woes, moon rocks and antibiotic candidates discovered with AI are all in this week’s news roundup.

PLAYMOBIL's little robot space explorer ROBert was reunited with ESA astronaut Matthias Maurer and ESA Kids mascot Paxi as they teamed up to meet young space fans at ESA's Space Days. Children had an absolute blast at ESA's Space Days, held at the PLAYMOBIL FunPark in Zirndorf, Germany from 30 May to 2 June 2024.

To date, astronomers have confirmed the existence of 5638 extrasolar planets in 4,199 star systems. In the process, scientists have found many worlds that have defied expectations. This is certainly the case regarding “hot Neptunes,” planets that are similar to the “ice giants” of the outer Solar System but orbit much closer to their stars. But when a Johns Hopkins University-led team of astronomers discovered TIC365102760 b (aka. Pheonix), they observed something entirely unexpected: a Neptune-sized planet that retained its atmosphere by puffing up.

Sam Grunblatt, an astrophysicist with JHU’s William H. Miller III Department of Physics and Astronomy, led the research. He was joined by an international team that included NSF Graduate Research Fellow Nicholas Saunders, 51 Pegasi b Fellows Shreyas Vissapragada, Steven Giacalone, Ashley Chontos, and Joseph M. Akana Murphy, as well as researchers from many prestigious institutes and universities. The paper that describes their findings (which recently appeared in The Astrophysical Journal) is part of a series titled “TESS Giants Transiting Giants.”

Artist’s impression of JG436b, a hot Neptune located about 33 light years from Earth. Credit: STScI

Puff planets are a new class of incredibly rare exoplanets, accounting for an estimated 1% of planets in our galaxy. The team discovered Pheonix by combining data from the Transiting Exoplanet Survey Satellite (TESS) with radial velocity measurements obtained by the High Resolution Echelle Spectrometer (HIRES) at the Keck Observatory. Their data indicated that Pheonix is 0.55 times the size of Jupiter but only 0.06 times as massive, which orbits a red giant star with a period of 4.21285 days (about six times closer to its star than the distance between Mercury and the Sun).

Based on the age and temperature of its star and the planet’s remarkably low density, the team expected that Pheonix’s gaseous envelopes should have been stripped away billions of years ago. Based on its density, the team also estimates that the planet is the puffiest “puff planet” discovered to date (roughly 60 times less dense than the densest “hot Neptune”) and that it will begin spiraling into its star in about 100 million years. As Grunblatt explained in a JHU HUB press release:

“This planet isn’t evolving the way we thought it would. It appears to have a much bigger, less dense atmosphere than we expected for these systems. How it held on to that atmosphere despite being so close to such a large host star is the big question.”

“It’s the smallest planet we’ve ever found around one of these red giants, and probably the lowest mass planet orbiting a [red] giant star we’ve ever seen. That’s why it looks really weird. We don’t know why it still has an atmosphere when other ‘hot Neptunes’ that are much smaller and much denser seem to be losing their atmospheres in much less extreme environments.”

Artist’s impression of Pheonix, the “hot Neptune” orbiting a red giant star 8 billion light-years from Earth. Credit: Roberto Molar Candanosa/JHU

These findings could have implications for new insight into the late-stage evolution of planetary systems and help scientists predict what will happen to the Solar System in a few billion years. According to standard models of stellar evolution, our Sun will exit its main sequence phase, expand to become a red giant, and eventually consume the inner planets. Based on these findings, they predict that Earth’s atmosphere may not evolve the way astronomers previously expected. Instead of our Sun blasting it away, our atmosphere may expand to become incredibly “puffy.”

Pheonix is the latest puffy planet examined by the international team based on TESS data. While puff planets are known to be rare, exoplanets like Pheonix are especially elusive because of their small size and low density. In the future, Grunblatt and his colleagues plan to search for more of these smaller worlds and have already identified a dozen potential candidates by combining transit and radial velocity data.

Further Reading: John Hopkins University, The Astrophysical Journal

The post Instead of Losing its Atmosphere, an Exoplanet Puffed Up and Held Onto it appeared first on Universe Today.

The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought. This time, it has detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang – one of the earliest galaxies ever observed.

“Earlier research suggested that carbon started to form in large quantities relatively late – about one billion years after the Big Bang,” said Kavli Institute Professor Roberto Maiolino. “But we’ve found that carbon formed much earlier – it might even be the oldest metal of all.”

‘Metal’ is the name astronomers give to any element heavier than hydrogen or helium, and seeing metals like carbon so early is a surprise. Carbon is, of course, one of the building blocks of life on Earth, but it also plays a role in galaxy and solar system formation. It is one of the materials that can accumulate in the protoplanetary disks around stars, snowballing to become planets, moons, and asteroids.

But astronomers weren’t expecting to see that process happening so early.

When the first stars (called population-III stars) were born, in an era of the universe known as Cosmic Dawn, the only plentiful elements around were hydrogen and helium. All heavier elements didn’t yet exist. They were only able to form later, inside the cores of stars, therefore wouldn’t be detectable until well after the deaths of the first stars.

Dying population-III stars that explode as supernovas throw their heavier elements out into the universe, allowing future populations of stars to develop rocky planets with more interesting chemistry.

The galaxy in question, named GS-z12, is thought to contain largely second generation stars, built from the remains of those first supernovas. Astronomers didn’t expect the building blocks of the galaxy to be carbon-rich:

“We were surprised to see carbon so early in the universe, since it was thought that the earliest stars produced much more oxygen than carbon,” said Maiolino. “We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently.”

JWST’s Near Infrared Spectrograph allowed astronomers to break down the light coming from the distant galaxy into its constituent parts, revealing all the different wavelengths present. Every element and chemical compound has its own signature when viewed via spectroscopy, and the signal for carbon was very strong. There was also a fainter signal for neon and oxygen, though those remain tentative detections for the moment.

How carbon emerged before oxygen is an open question, but one hypothesis proposes that scientists now need to revisit their models of population-III star supernovas. If these supernovas occurred with less energy than previously thought, then they would scatter carbon from the stars’ outer shells, while most of the oxygen present would be captured within the event horizon as the stars collapsed into black holes.

Regardless of how it happened, there is now a strong case for heavy elements early in the universe – far earlier than anyone guessed. JWST is revealing unexpected details about the first galaxies that will ultimately make scientists’ predictions about the evolution of the universe far more robust. And perhaps most significantly, it also tells us about the very first step towards creating life.

“These observations tell us that carbon can be enriched quickly in the early universe,” said Francesco D’Eugenio of the Kavli Institute. “And because carbon is fundamental to life as we know it, it’s not necessarily true that life must have evolved much later in the universe. Perhaps life emerged much earlier – although if there’s life elsewhere in the universe, it might have evolved very differently than it did here on Earth.”

Learn More:

“Earliest detection of metal challenges what we know about the first galaxies.” University of Cambridge.

D’Eugenio et al. “JADES: Carbon enrichment 350 Myr after the Big Bang in a gas-rich galaxy.” ArXiv preprint (accepted to Astronomy & Astrophysics).

The post Carbon is Surprisingly Abundant in an Early Galaxy appeared first on Universe Today.

An exclusive look at "Dune: The Graphic Novel, Book 3: The Prophet," which comes out on July 16.

The three-body problem is a physics conundrum that has boggled scientists since Isaac Newton's day. But what is it, why is it so hard to solve and is the sci-fi series of the same name really possible?

World leaders must make plans to remove more carbon dioxide from the atmosphere, a new report says

Two astronauts performed tests inside full-scale mock ups of SpaceX’s Starship Human Landing System to test spacesuits and other hardware for NASA's Artemis 3 moon mission.

Prospective memory is a skill that can be practiced, making it more likely that someone can remember an appointment or meet a deadline

An interview with Raven Baxter and NASA's Ronald Gamble about the Stellar Dreams Project, which will give 100 telescopes to 100 families.

Magnificent island universe