Two “Super Mercury” Exoplanets Found in a Single System

Mercury gives a clue to Super-Mercuries
Astronomers have found a star system with two planets like Mercury, but bigger. Our own Mercury could supply clues to their composition and formation. (Credit: NASA/Johns Hopkins University/Applied Physics Laboratory.Carnegie Institution of Washington).

There’s a star system out there with three super-Earth planets and two super-Mercuries. Super-Earths are fairly familiar types of exoplanets, but super-Mercuries are rare. Those are planets with the same composition as our own Mercury, but larger and denser. Yet, here’s HD 23472, showing off two of eight known super-Mercuries in the galaxy.

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A Computer Algorithm is 88% Accurate in Finding Gravitational Lenses

Pictures of gravitational lenses from the AGEL survey. Credit: ARC Centre of Excellence for All Sky Astrophysics in 3-Dimensions (ASTRO3D) and the University of NSW (UNSW).

Astronomers have been assessing a new machine learning algorithm to determine how reliable it is for finding gravitational lenses hidden in images from all sky surveys. This type of AI was used to find about 5,000 potential gravitational lenses, which needed to be confirmed. Using spectroscopy for confirmation, the international team has now determined the technique has a whopping 88% success rate, which means this new tool could be used to find thousands more of these magical quirks of physics.

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A Single High-Resolution Image of Dimorphos Stacked From DART’s Final Images

A high resolution image of Dimorphos made by stacking the last images received from DART. Credit: Eydeet on Imgur.

Here’s a sharper view of Dimorphos, the small asteroid moonlet that the DART (Double Asteroid Redirection Test) spacecraft intentionally crashed into. Eydeet on Imgur created a higher resolution image of Dimorphos by stacking the last few images received from the spacecraft before impact.

First impressions? It’s an egg-shaped rubble pile.

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A Dwarf Galaxy Passed Close to the Milky Way and Left Ripples in its Wake

Artist's view of ripples on the edge of the Milky Way. Credit: NASA JPL-Caltech R. Hurt (SSC Caltech)

When you imagine the collision of galaxies, you probably think of something violent and transformational. Spiral arms ripped apart, stars colliding, cats and dogs living together, mass hysteria. The reality is much less dramatic. As a recent study shows, our galaxy is in a collision right now.

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Stars Spiral Inward to the Cores of Stellar Nurseries

Image of NGC 346, a stellar nursery where astronomers have discovered newborn stars spiralling in towards the center of a nebula
Astronomers have been bemused to find young stars spiralling into the centre of a massive cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way. The outer arm of the spiral in this huge, oddly shaped stellar nursery — called NGC 346 — may be feeding star formation in a river-like motion of gas and stars. This is an efficient way to fuel star birth, researchers say.

Astronomers studying a stellar cluster within the Small Magellanic Cloud (SMC) have found young stars spiraling in towards the center of the cluster. The cluster, NGC 346, is an open cluster embedded within a glowing cloud of gas, which is typical of stellar nurseries – places where new stars are formed. The outer spiral arm of this star forming region appears to be funneling gas, dust and new stars into the center, which researchers describe as an efficient way to fuel the birth of new stars.

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Mysterious Europa Gets an Extreme Closeup From NASA’s Juno Probe

Juno's view of Europa
The ridges and troughs on Europa stand out in an image from NASA's Juno orbiter. (NASA / JPL-Caltech / SwRI / MSSS / Björn Jónsson)

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.

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The Moon was Pummeled by Asteroids at the Same Time the Dinosaurs Died. Coincidence?

Earth and possibly its Moon were hit by impactors that killed off the dinosaurs
Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too? Credit: NASA

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.

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DART Impact Seen by Hubble and Webb

DART hits an asteroid.
For the first time, the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope took simultaneous observations of the same target. These images, Hubble on left and Webb on the right, show observations of Dimorphos several hours after NASA’s Double Asteroid Redirection Test (DART) intentionally impacted the moonlet asteroid. Courtesy NASA, ESA, CSA, and STScI

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.

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NASA and SpaceX Will Study Low-Cost Plan to Give Hubble a Boost

Hubble Space Telescope
NASA's Hubble Space Telescope flies with Earth in the background after a 2002 servicing mission. Credit: NASA.

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.

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The First Telescope Images of DART's Impact are Starting to Arrive

Artist's impression of the DART mission impacting the moonlet Dimorphos. Credit: ESA

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.

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