Universe Today

July 18, 2024July 18, 2024 by Laurence Tognetti

Officially, Only the Sun Can Have Planets. Is it Time to Fix the Definition of “Planet”?

Color-enhanced image of Pluto obtained from NASA’s New Horizons spacecraft in July 2015. (Credit: NASA / Johns Hopkins University Applied Physics Laboratory (JHUAPL) / Southwest Research Institute (SwRI))

What is the true definition of a planet, and could there be a more refined definition in the future? This is what a recent study published in The Planetary Science Journal hopes to address as a team of researchers from the United States and Canada investigated the potential for a new definition of a “planet”. This study holds the potential to challenge the longstanding definition outlined by the International Astronomical Union (IAU), which established IAU Resolution B5 in 2006, resulting in demoting Pluto from a “planet” to a “dwarf planet”.

July 17, 2024July 17, 2024 by Carolyn Collins Petersen

Neutron Star is Spraying Jets Like a Garden Sprinkler

Radio image from the MeerKAT telescope showing Circinus X-1 in the center, within the spherical remnant of the supernova it was born in. The shock waves caaued by the jets are seen above and below Cir X-1, and the S-shape structure in the jets is somewhat obscured by a bright source in the background. Courtesy Fraser Cowie, Attribution CC BY 4.0. — Radio image from the MeerKAT telescope showing Circinus X-1 in the center, within the spherical remnant of the supernova it was born in. The shock waves caused by the jets are seen above and below Cir X-1, and the S-shape structure in the jets is somewhat obscured by a bright source in the background. Courtesy Fraser Cowie, Attribution CC BY 4.0.

X-ray binaries are some of the oddest ducks in the cosmic zoo and they attract attention across thousands of light-years. Now, astronomers have captured new high-resolution radio images of the first one ever discovered. It’s called Circinus X-1. Their views show a weird kind of jet emanating from the neutron star member of the binary. The jet rotates like an off-axis sprinkler as it spews material out through surrounding space, sending shockwaves through the interstellar medium.

July 17, 2024July 17, 2024 by Alan Boyle

NASA Stops Work on VIPER Moon Rover, Citing Cost and Schedule Issues

NASA VIPER rover in clean room — NASA’s VIPER rover sits assembled inside the clean room at the agency’s Johnson Space Center in Texas. (Credit: NASA)

NASA says it intends to discontinue development of its VIPER moon rover, due to cost increases and schedule delays — but the agency is also pointing to other opportunities for robotic exploration of the lunar south polar region.

July 17, 2024July 17, 2024 by Evan Gough

Experimental Radar Technique Reveals the Composition of Titan’s Seas

This colorized mosaic from NASA's Cassini mission shows the most complete view yet of Titan's northern land of lakes and seas. Saturn's moon Titan is the only world in our solar system other than Earth that has stable liquid on its surface. The liquid in Titan's lakes and seas is mostly methane and ethane. New bistatic radar data from Cassini is revealing even more detail about Titan's hydrocarbon seas. Image Credit: NASA / JPL-Caltech / Agenzia Spaziale Italiana / USGS

The Cassini-Huygens mission to Saturn generated so much data that giving it a definitive value is impossible. It’s sufficient to say that the amount is vast and that multiple scientific instruments generated it. One of those instruments was a radar designed to see through Titan’s thick atmosphere and catch a scientific glimpse of the moon’s extraordinary surface.

Scientists are still making new discoveries with all this data.

July 17, 2024July 17, 2024 by Andy Tomaswick

Webb Measures the Weather on a Tidally Locked Exoplanet

Exploring exoplanet atmospheres in more detail was one task that planetary scientists anticipated during the long wait while the James Webb Space Telescope (JWST) was in development. Now, their patience is finally paying off. News about discoveries of exoplanet atmosphere using data from JWST seems to be coming from one research group or another almost every week, and this week is no exception. A paper published in Nature by authors from a few dozen institutions describes the atmospheric differences between the “morning” and “evening” sides of a tidally locked planet for the first time.

July 16, 2024July 16, 2024 by Carolyn Collins Petersen

More Than Half of Near Earth Objects Could Be “Dark Comets”

An artist's concept of a dark comet floating in space. Courtesy Nicole Smith.

Next time you’re visiting the seaside or a large lake, or even sipping a frosty glass of water, think about where it all originated. There are many pathways that water could have taken to the infant Earth: via comets, “wet asteroids”, and outgassing from early volcanism. Aster Taylor, a University of Michigan graduate student has another idea: dark comets. They’re something of a cross between asteroids and comets and could have played a role in water delivery to our planet.

July 16, 2024July 16, 2024 by Matt Williams

New Images From Webb Reveal Jupiter's Complex Atmosphere

New observations of the Great Red Spot on Jupiter have revealed that the planet’s atmosphere above and around the infamous storm is surprisingly interesting and active. Credit: ESA

The James Webb Space Telescope (JWST) has accomplished some spectacular feats since it began operations in 2021. Thanks to its sensitivity in the near- and mid-infrared wavelengths, it can take detailed images of cooler objects and reveal things that would otherwise go unnoticed. This includes the iconic image Webb took of Jupiter in August 2022, which showed the planet’s atmospheric features (including its polar aurorae and Great Red Spot) in a new light. Using Webb, a team of European astronomers recently observed the region above the Great Red Spot and discovered previously unseen features.

July 16, 2024July 16, 2024 by Mark Thompson

Pulsars are the Ideal Probes for Dark Matter

This artist's concept shows a pulsar, which is like a lighthouse, as its light appears in regular pulses as it rotates. Pulsars are dense remnants of exploded stars, and are part of a class of objects called neutron stars. http://photojournal.jpl.nasa.gov/catalog/PIA21085 Credit NASA/JPL-Caltech

Pulsars are the remnants of the explosion of massive stars at the end of their lives. The event is known as a supernova and as they rapidly spin they sweep a high energy beam across the cosmos much like a lighthouse. The alignment of some pulsar beams mean they sweep across Earth predictably and with precise regularity. They can be, and often are used as timing gauges but a team of astronomers have found subtle timing changes in some pulsars hinting at unseen mass between pulsars and telescopes—possibly dark matter entities.

July 16, 2024July 16, 2024 by Mark Thompson

Webb Maps the Weather on the Closest Brown Dwarfs to Earth

An artist’s impression of the nearest brown dwarf to Earth, WISE 1049AB, (pictured main), along with an impression of the stormy weather on a brown dwarf planet (inset). Credit ESO-I. Crossfield-N. Risinger

James Webb Space Telescope (JWST) has done it again. A team of astronomers have used it to map the weather on a pair of brown dwarf stars. Infrared light was analysed from the pair and its variation over time was measured. The team were able to generate a 3D picture of the weather and discovered gasses in the atmosphere like water vapour, methane and carbon dioxide. Swirling clouds of hot sand were also found with temperatures reaching as high as 950 C!

July 16, 2024July 16, 2024 by Evan Gough

Astronauts Struggle To Eat Their Space Food and Scientists Want to Know Why

Researchers in Australia used Virtual Reality to understand why food tastes bland to astronauts. Image Credit: Seamus Daniel, RMIT University. CC BY-SA

Astronauts sometimes struggle to consume enough nutritious food on the ISS because it tastes bland. But astronaut food is of high quality and designed to be palatable and to meet nutrition needs. What’s the problem?