Space News & Blog Articles

Over the course of a brief two-hour opportunity, NASA’s Juno spacecraft captured a rare close look at Europa, an ice-covered moon of Jupiter that’s thought to harbor a hidden ocean — and perhaps an extraterrestrial strain of marine life.

Juno has been orbiting Jupiter since 2016, but this week brought the best opportunity to look at Europa, which is the prime target for investigation by NASA’s Europa Clipper probe in the 2030s. On Sept. 29, the orbiter buzzed over the moon’s surface at a velocity in excess of 52,000 mph (23.6 km per second), and at an altitude of 352 kilometers (219 miles).

That’s as close as any spacecraft has come to Europa since the Galileo orbiter’s 218-mile flyby in 2000.

The spacecraft’s JunoCam imager is designed mostly for public engagement purposes — and over the past six years, image-processing fans have helped NASA bring stunning pictures of Jupiter to the public. Now they’re doing much the same for JunoCam’s photos of Europa.

In the first image sent back by the spacecraft, focusing on an area near Europa’s equator known as Annwn Regio, you can make out the trademark ridges and troughs of Europa’s icy shell. The cracks in the ice are thought to be caused by the tidal forces that are generated as Europa orbits Jupiter.

It only takes a quick look at the Moon to see its impact-beaten surface. There are craters everywhere. Some of those impact sites apparently date back to the same time some very large asteroids were whacking Earth. One of them formed Chixculub Crater under the Yucatan Peninsula. That impact set in motion catastrophic events that wiped out much of life on Earth, including the dinosaurs.

Did some of the craters on the Moon form from the same asteroid swarm that impacted Earth and precipitated the demise of the dinosaurs? Chang’e 5 samples from specific craters on the Moon seem to show that this could well have happened.

That’s the conclusion a group of Australian scientists came to after studying glass beads from the Moon. They outlined their findings in a paper about the science they performed on samples picked up from the Moon by the Chang’e 5 Lunar mission. The beads were created by the heat and pressure caused by meteoritic impacts on the Moon. The lead author of the paper, Professor Alexander Nemchin, from Curtin University’s Space Science and Technology Centre (SSTC) in the School of Earth and Planetary Sciences, said the findings imply that the timing and frequency of asteroid impacts on the Moon may have been mirrored on Earth. If so then the find tells us more about the history of the evolution of our own planet.

“We combined a wide range of microscopic analytical techniques, numerical modeling, and geological surveys to determine how these microscopic glass beads from the Moon were formed and when,” Professor Nemchin said. “We found that some of the age groups of the lunar glass beads coincide precisely with the ages of some of the largest terrestrial impact crater events, including the Chicxulub impact crater responsible for the dinosaur extinction event.”

Glass beads collected by the Chang’e 5 mission date back some 66 million years and could have formed from impacts. Courtesy Beijing SHRIMP Center, Institute of Geology, CAGS

What happens when you whack a little asteroid with an even littler spacecraft? People around the world watched on the 26th of September when the DART mission smashed into the side of Dimorphos. This tiny worldlet is a companion asteroid to Didymos. It was the world’s first test of the kinetic impact technique, using a spacecraft to deflect an asteroid by modifying its orbit. Amateur observer networks and professional observatories tracked the meetup from the ground. In a first, both Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST) took simultaneous images and data.

Together, they managed to track the asteroid before the event. Then, they got images and data about the ejecta (the material that got flung away from it) afterward. Each set of images showed streaks of ejecta stretching out away from the little asteroid. Scientists could even tell exactly where the spacecraft hit the asteroid. The data should tell them about the asteroid’s composition and structure. Eventually, they should find out how much the impact affected Dimorphosis’s orbit.

Doin’ it with DART

The collision of spacecraft and an asteroid posed a challenge for observers. That’s because Dimorphos and its companion Didymos move fairly quickly in their orbits. Ground-based observers were able to track the faint objects fairly well, and networks of smaller telescopes caught a view of the collision and its aftermath.

For JWST, tracking that action isn’t exactly what the telescope was built for, but the teams managed. Flight operations, planning, and science teams for JWST had to come up with a method to track the asteroids. They actually move faster than JWST was originally programmed for, so that had to be taken into account. JWST watched the event using its Near-Infrared Camera (NIRCam). Webb observed the impact over five hours total and captured 10 images.

JWST captured this sequence of the DART collision on Dimorphos. Courtesy NASA, ESA, CSA, and STScI.

NASA and SpaceX say they’ll conduct a feasibility study into a plan to reboost the 32-year-old Hubble Space Telescope to a more sustainable orbit, potentially at little or no cost to NASA.

The plan could follow the model set by last year’s Inspiration4 mission, an orbital trip that was facilitated by SpaceX and paid for by tech billionaire Jared Isaacman as a philanthropic venture. Isaacman, who is now spearheading a privately funded space program called Polaris in cooperation with SpaceX, says he’ll participate in the feasibility study.

“We could be taking advantage of everything that’s been developed within the commercial space industry to execute on a mission, should the study warrant it, with little or no potential cost to the government,” Isaacman said at a news briefing.

If the six-month feasibility study turns into an actual mission, a spacecraft could be sent up to Hubble to lift the telescope from its current altitude of 330 miles to the 370-mile orbit it was in when it was deployed in 1990. Patrick Crouse, Hubble project manager at NASA’s Goddard Space Flight Center, said that could add another 15 to 20 years to the telescope’s life.

But if the study finds that the reboost mission would be unrealistic, NASA would have to come up with a way to deorbit or dispose of the 12-ton telescope safely in the 2030 time frame, Crouse said.

On September 26th, at 23:14 UTC (07:14 PM EST; 04:14 PM PST), NASA’s Double Asteroid Redirect Test (DART) spacecraft successfully struck the 160-meter (525 ft) moonlet Dimorphos that orbits the larger Didymos asteroid. The event was live-streamed all around the world and showed footage from DART’s Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) as it rapidly approached Dimorphos. In the last few seconds, DART was close enough that individual boulders could be seen on the moonlet’s surface.

About 38 seconds after impact, the time it took the signal to reach Earth, the live stream ended, signaling that DART had successfully impacted Dimorphos and was destroyed in the process. Meanwhile, teams of astronomers stretching from the Indian Ocean to the Arabian Peninsula watched the impact with their telescopes. One, in particular – the Les Makes Observatory on the island of Le Reunion in the Indian Ocean – captured multiple images of the impact. These were used to create a real-time video and show the asteroid brightening as it was pushed away, followed by material ejected from the surface.

The observation campaign was organized by the ESA’s Planetary Defence Office (PDO) and coordinated by the Agency’s Near-Earth Object Coordination Centre (NEOCC). This campaign was one of several worldwide that coincided with DART’s successful test of the kinetic impact method. While not all observation stations were successful due to cloud cover, technical problems, and other issues, the ESA campaign acquired several stunning images showing the kinetic impactor hitting its target and what immediately followed.

“Something like this has never been done before, and we weren’t entirely sure what to expect,” said Marco Micheli, an Astronomer at the NEOCC. “It was an emotional moment for us as the footage came in.”

As you can see from the video (posted above), the asteroid immediately started brightening upon impact and was many times brighter within seconds. This indicated that the moonlet’s trajectory was altered, causing more sunlight to be reflected from its surface. Less than a minute after impact, a cloud of ejected material became visible as it drifted into the path of direct sunlight and began reflecting it. The time-lapse video shows (in thirteen seconds) what took place over roughly half an hour. As Dora Föhring, another NEOCC astronomer, adds: