Tag: science

InSight detects and dates large impact on Mars

11:14 am

InSight's Christmas Eve impact
Click for full image.

Using the data from InSight’s seismometer of a 4 magnitude earthquake on Mars on December 24, 2021, scientists were able to use the high resolution camera on Mars Reconnaissance Orbiter (MRO) to find the meteorite impact that produced that quake, the largest detected since spacecraft have been visiting Mars. The picture to the right, cropped and reduced to post here and unveiled at yesterday’s press conference, shows the new crater.

The meteoroid is estimated to have spanned 16 to 39 feet (5 to 12 meters) – small enough that it would have burned up in Earth’s atmosphere, but not in Mars’ thin atmosphere, which is just 1% as dense as our planet’s. The impact, in a region called Amazonis Planitia, blasted a crater roughly 492 feet (150 meters) across and 70 feet (21 meters) deep. Some of the ejecta thrown by the impact flew as far as 23 miles (37 kilometers) away.

With images and seismic data documenting the event, this is believed to be one of the largest craters ever witnessed forming any place in the solar system.

This is not the first such impact identified from InSight seismic data, but it is the largest. The white streaks surrounding the crater are thought to be near-surface ice ejected at impact.

The overview map below provides further context, as well as showing us the proximity of this impact to the proposed Starship landing sites on Mars.
» Read more

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Past tree ring spikes in carbon-14 were likely not caused by solar flares

9:41 am

The uncertainty of science: According to researchers, past tree ring spikes in carbon-14 found in found at five different times going back seven thousand years were likely not caused by solar flares, as previously thought.

The team behind the new research created software to analyse every available piece of data on tree rings, producing the most comprehensive research on Miyake events to date. They found that the events didn’t show a consistent relationship to the 11-year solar cycle, which is the cycle that the Sun’s magnetic field goes through. (Currently we’re heading towards the solar maximum which means more sunspots and solar flares.)

This lack of relationship to the solar cycle means that Miyake events probably aren’t due to a solar flare, as flares occur more during the solar maximum.

The scientists also found that the events lasted years, not days as one would expect by a solar flare.

You can read their paper here. The bottom line is that the cause of these spikes remains unknown.

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A glacier sea on Mars

6:12 pm

A glacier sea on Mars
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Cool image time! The photo to the right, rotated, cropped, and reduced to post here, should at first glance be one of my “What the heck!?” images. However, a little detective work quickly provides us some understanding of the inexplicable geology seen at this particular location on Mars.

The picture was taken on August 29, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and was labeled by the science team a “Lobate Debris Apron in Deuteronilus Mensae.” This mensae region is the western part of the 2,000-mile-long strip in the northern mid-latitudes of Mars that I label glacier country, since almost every high resolution picture taken in this strip shows extensive glacial features.

This picture is no different, showing what appears to be glaciers, but by itself it is still difficult to make sense of it. Glaciers flow downhill, like rivers. In this high resolution image the direction of flow is somewhat unclear.

As always, a wider view clarifies the picture.
» Read more

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Martian rectilinear ridges

1:16 pm

Martian rectilinear ridges
Click for original image.

Today’s cool image is also a bafflement. The photo to the right, cropped, reduced, and enhanced to post here, was taken on July 25, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The ridges in this picture are labeled by the scientists “Rectilinear Ridges,” but they really do not resemble any of the Martian rectilinear ridge types outlined in this paper [pdf], all of which appear to have a much more pronounced criss-cross pattern.

These ridges however are more meandering, and instead to my eye seem more like inverted channels, ancient channels whose beds became compacted and then became ridges when the less dense surrounding material eroded away. The problem with this conclusion however is the lack of any obvious tributary pattern. If these were once channels where either liquid water or glaciers once flowed, none of them seem to exhibit any drainage pattern. The ridges go in all directions.

The context map below only increases the mystery.
» Read more

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Lucy’s view of the Earth-Moon system during its October fly-by

8:35 am

The Earth and Moon system, as seen by Lucy
Click for original image.

Lucy's planned route
Lucy’s planned route to explore the Trojan asteroids

In the days prior to its October 16, 2022 fly-by of the Earth, the Lucy asteroid probe took several calibration images of the Earth and the Moon. The photo above, cropped, reduced, and enhanced to post here, shows both the Earth and the Moon together. From the caption:

On October 13, 2022, NASA’s Lucy spacecraft captured this image of the Earth and the Moon from a distance of 890,000 miles (1.4 million km). The image was taken as part of an instrument calibration sequence as the spacecraft approached Earth for its first of three Earth gravity assists. These Earth flybys provide Lucy with the speed required to reach the Trojan asteroids — small bodies that orbit the Sun at the same distance as Jupiter.

In the original, the Moon is so dim, compared to the Earth, that it was hard to find in the picture. I therefore brightened it considerably more than the Earth to make it easily seen above.

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After 50 years Edward Stone retires as the project scientist for Voyagers 1 and 2

8:23 am

Edward Stone, the only project scientist the interstellar spacecraft Voyagers 1 and 2 have ever known, has now retired after 50 years service.

Stone accepted scientific leadership of the historic mission in 1972, five years before the launch of its two spacecraft, Voyager 1 and Voyager 2. Under his guidance, the Voyagers explored the four giant planets and became the first human-made objects to reach interstellar space, the region between the stars containing material generated by the death of nearby stars.

Until now, Stone was the only person to have served as project scientist for Voyager, maintaining his position even while serving as director of NASA’s Jet Propulsion Laboratory in Southern California from 1991 to 2001. JPL manages the Voyager mission for NASA. Stone retired from JPL in 2001 but continued to serve as the mission’s project scientist.

The new Voyager project scientist however is not new to the project.

Linda Spilker will succeed Stone as Voyager’s project scientist as the twin probes continue to explore interstellar space. Spilker was a member of the Voyager science team during the mission’s flybys of Jupiter, Saturn, Uranus, and Neptune. She later became project scientist for NASA’s now-retired Cassini mission to Saturn, and rejoined Voyager as deputy project scientist in 2021.

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A hole in space

8:48 am

A hole in space
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and was released today as its picture of the week. From the caption:

This peculiar portrait from the NASA/ESA Hubble Space Telescope showcases NGC 1999, a reflection nebula in the constellation Orion. NGC 1999 is around 1350 light-years from Earth and lies near to the Orion Nebula, the closest region of massive star formation to Earth. NGC 1999 itself is a relic of recent star formation — it is composed of detritus left over from the formation of a newborn star.

Just like fog curling around a street lamp, reflection nebulae like NGC 1999 only shine because of the light from an embedded source. In the case of NGC 1999, this source is the aforementioned newborn star V380 Orionis which is visible at the centre of this image. The most notable aspect of NGC 1999’s appearance, however, is the conspicuous hole in its centre, which resembles an inky-black keyhole of cosmic proportions.

Once astronomers thought the black area was caused by dust, blocking the light. Now, based on a lot of new data from multiple ground- and space-based telescopes, they know that it actually is a black empty void. Why it exists however is not yet understood.

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Bedrock layers in Terby Crater on Mars

5:55 pm

Bedrock layers in Terby Crater on Mars
Click for full image.

Cool image to end the week! The picture to the right, rotated, cropped, reduced, and enhanced to post here, was taken by on July 18, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the bedrock layers on one of two very large mesas that jut out into the floor of 108-mile-wide Terby Crater.

I want to focus your eye on the spoon-shaped mesa near the top right of the photo. Note how the layers can be seen on both sides, even though the top of the mesa seems to be concave. This is strange and complex geology, made even more fascinating in that the two mesas almost reach the center of the crater floor. Why are they here? Why were they not flattened during impact, like the rest of the crater floor? Or maybe the original crater floor is the mesa top, but if so, why did the rest of the crater interior get eroded away.

The overview map below provides some context, and helps fill in some details, even if it fails to answer any of these questions.
» Read more

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Astronomers discover an exoplanet with the density of a marshmallow

10:18 am

Using ground-based telescopes to gather more data about an exoplanet discovered by the orbiting TESS telescope, astronomers have found that it has the density of a marshmallow.

The planet orbits a red dwarf star, the most common star in the universe, and is the “fluffiest” yet seen around this type of star.

Red dwarf stars are the smallest and dimmest members of so-called main-sequence stars — stars that convert hydrogen into helium in their cores at a steady rate. Though “cool” compared to stars like our Sun, red dwarf stars can be extremely active and erupt with powerful flares capable of stripping a planet of its atmosphere, making this star system a seemingly inhospitable location to form such a gossamer planet.

Astronomers remain puzzled how such a large fluffy planet could have formed around such a dim small star.

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Rate of micrometeorite impacts on Webb holding as expected

10:10 am

According to this Space.com article, the rate and size of micrometeorite impacts on the main mirror of the Webb Space Telescope has held steady at the rate and size expected, since the first surprisingly large micrometeorite impact in May that slightly dinged one mirror segment.

At this point, JWST has experienced a total of 33 micrometeoroid events, according to Smith’s slides. But the most damaging one came before JWST began science observations; in late May, a particularly large micrometeoroid struck the observatory’s mirror, leaving its mark on one golden hexagon. The team estimates that a strike of that size should occur about once a year, Smith said.

“So we got that at month five,” he said. “We haven’t seen another one yet, so it’s still consistent with the statistics that we expected.”

Smith noted that, at the current impact rate, Webb will still be meeting its five-year performance requirement 10 years into the mission. Scientists estimate that the observatory has enough fuel to operate for 20 years.

Meanwhile, one of Webb’s infrared cameras is not doing spectroscopy as engineers analyze the high levels of friction in a “grating wheel.” At this point it appears they still do not understand the cause of the friction, and thus have not come up with a plan for mitigating it.

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Chandrayaan-3 now scheduled for summer 2023

10:01 am

India’s second attempt to put a rover on the surface of the Moon, Chandrayaan-3, has now been tentatively scheduled for launch in the summer of 2023.

The launch had originally been scheduled for launch in the fall of 2020, but was delayed when India shut down due to the Wuhan panic. Official at ISRO, India’s space agency, had hoped to launch by the summer of 2022, but that proved impossible. They have now delayed the mission a full year.

In fact, all earlier reports had indicated the rover was almost ready. This new delay of a full year suggests that some new issues might have been identified.

The news article at the link also notes that ISRO is now planning two unmanned orbital missions plus four launch abort tests before launching its first manned mission, dubbed Gaganyaan, not two abort tests as previously planned. They are still targeting ’24 for the manned mission.

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