Tag: science

Inverted river on Mars

1:52 pm

Inverted river on Mars

Cool image time! The photo to the right, rotated, cropped, reduced, and enhanced to post here, was taken on May 30, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists label as a “inverted fluvial system”.

Such features are not unusual on Mars. The theory explaining their formation is that this was once a channel where either water or ice flowed, packing the streambed down so that it was more dense than the surrounding terrain. After the flowing material disappeared, the less dense surrounding terrain eroded away, leaving the channel as a meandering ridge.

The location of this inverted channel, as shown in the overview map below, lends some weight to the flowing material being water or ice.
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ESA looking to SpaceX to launch Euclid space telescope

9:02 am

Capitalism in space: Having lost its Soyuz launch vehicle for its Euclid space telescope because of the Russian invasion of the Ukraine, the European Space Agency (ESA) is now looking at SpaceX as a possible option.

At a meeting of NASA’s Astrophysics Advisory Council, Mark Clampin, director of the agency’s astrophysics division, said his understanding is that the European Space Agency was leaning towards launching its Euclid mission on a Falcon 9 in mid to late 2023.

NASA is a partner on Euclid, a space telescope that will operate around the Earth-sun L-2 Lagrange point 1.5 million kilometers from Earth to study dark energy, dark matter and other aspects of cosmology. The 2,160-kilogram spacecraft was to launch on a Soyuz rocket from French Guiana in 2023.

Europe has for years used its own rockets for its science missions. However, right now the Falcon 9 appears the only option. The last launches of Europe’s Ariane-5 rocket are already assigned, and the new Ariane-6 rocket has not yet flown, is behind schedule, and its early launches are also already reserved.

Nor does ESA have other options outside of SpaceX. Of the rockets powerful enough to do the job, ULA’s Atlas-5 is also being retired, and the Vulcan rocket is as yet unavailable. Blue Origin’s New Glenn is years behind schedule, with no clear idea when it will finally launch.

A final decision is expected soon. ESA could either go with SpaceX, or simply delay several years until Ariane-6 is flying.

If SpaceX gets the job however it will once again demonstrate the value of moving fast in a competitive environment. While its competitors have dithered and thus do not have their rockets ready, SpaceX has been flying steadily for years, so it gets the business.

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After 30 years the Geotail solar probe appears dead

8:01 pm

Launched in 1992 as a joint U.S./Japan project to study the tail of the Earth’s magnetosphere, the Geotail solar mission appears to be over, though engineers continue to work the problem.

Originally, Geotail was equipped with two data recorders to collect the mission’s scientific data. One data recorder failed in 2012 after 20 years of gathering information about the plasma environment around Earth. The remaining data recorder continued collecting data for 10 more years until it experienced an anomaly on June 28, 2022.

The team at JAXA discovered the error with the recorder and have been performing tests to investigate the cause and extent of the damage. Ongoing attempts to recover the recorder have been unsuccessful. Without a functioning recorder, the science data from the U.S. instruments can no longer be collected or downlinked. NASA, ISAS, and JAXA are deciding the best path forward for the mission given the failure.

When the solar wind hits the Earth’s magnetosphere, it pushes it away so that on the side away from the Sun a tail forms, almost like the wake of a ship.

Without any way to download the spacecraft’s data, however, Geotail’s value as a scientific probe is extremely limited. If engineers can still control it and adjust its orbit, however, then it might still be useful for a variety of engineering and orbital flight tests.

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Jets from baby stars

12:12 pm

Jets from baby stars
Click for full image.

Cool image time! The picture to the right, rotated and reduced to post here, was taken across multiple wavelengths by the Hubble Space Telescope and shows two different Herbig–Haro objects (HH 1 at the top and HH 2 on the bottom). Herbig-Haro objects are the bright cloud clumps found near newly formed baby stars. These particular clouds are about 1,250 light years away. The jets flowing away from HH 1 are speeding away at about 250 miles per second.

Note that the baby stars themselves are not visible, buried in the dust that surrounds them. The bright star in the upper right is an unrelated foreground star.

In the case of HH 1/2, two groups of astronomers requested Hubble observations for two different studies. The first delved into the structure and motion of the Herbig–Haro objects visible in this image, giving astronomers a better understanding of the physical processes occurring when outflows from young stars collide with surrounding gas and dust. The second study instead investigated the outflows themselves to lay the groundwork for future observations with the NASA/ESA/CSA James Webb Space Telescope. Webb, with its ability to peer past the clouds of dust enveloping young stars, will revolutionise the study of outflows from young stars.

There is a lot of complexity here that this image only hints at. Note for example the smaller cloud objects near HH1, the shape of which suggest a shaping by some interstellar wind.

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OSIRIS-REx does mid-course correction

8:36 am

To better refine its path back to Earth in order to properly aim its sample return capsule, engineers had OSIRIS-REx do a short successful 30 second engine burn on September 21, 2022.

Nor will this be the only course correction prior to sample return on September 24, 2023 in Utah.

To ensure a safe delivery, “Over the next year, we will gradually adjust the OSIRIS-REx trajectory to target the spacecraft closer to Earth,” said Daniel Wibben, trajectory-and-maneuver design lead with KinetX Inc. “We have to cross Earth’s orbit at the time that Earth will be at that same location.” Wibben works closely with the Lockheed Martin team in Littleton, Colorado, that flies the spacecraft.

Last month’s maneuver was the first time the OSIRIS-REx team changed the spacecraft’s trajectory since it left Bennu on May 10, 2021. Following this course adjustment, OSIRIS-REx would pass about 1,367 miles (2,200 kilometers) from Earth. A series of maneuvers beginning in July 2023 will bring OSIRIS-REx even closer, to 155 miles (250 kilometers) off the surface, close enough to release its sample capsule for a precision landing – via parachute at the Air Force’s Utah Test and Training Range in the Great Salt Lake Desert.

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Two solar eclipses coming to the U.S. next year

12:47 pm

The next eclipses to cross the U.S.
Map by Michael Zeiler (GreatAmericanEclipse.com). Click for original.

The U.S. public will get to see two different solar eclipses during a six month period, starting one year from today.

The map to the right, cropped and reduced to post here, shows the dates and the path of both eclipses.

On 14 October 2023, anyone under clear skies within a path that sweeps from Oregon to Texas and then through parts of Central and South America will see an annular (“ring”) eclipse. Just six months later, on 8 April 2024, a total solar eclipse will sweep from Mexico to Texas to the Canadian Maritimes, plunging day into night and revealing the magnificent solar corona for anyone fortunate to be within the path of totality and under clear skies. Nearly everyone in North America will have a partial solar eclipse both days.

As always with eclipses, great care must be taken to watch it. With the 2017 eclipse Diane and I had good filters, but even so I noticed my eyes were very tired for several days afterward.

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Perseverance spots Phobos

10:57 am

Phobos, as seen by Perseverance on Mars
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on January 12, 2022 by one of the high resolution cameras on the Mars rover Perseverance, and shows the Martian moon Phobos.

As noted in an update today by Claire Newman, one of the members of the science team,

This provides a measurement, using visible light, of the amount of dust in the nighttime atmosphere, which can be compared to similar measurements made by looking at the sun during the daytime, and to nighttime measurements of dust abundance made in the infrared by MEDA [another Perseverance instrument].

There have been three attempts to land on Phobos, all by the Russians, all of which failed. At present a Japanese mission to Phobos, dubbed Mars Moons eXploration or MMX, is scheduled to launch in 2024. This is a planned sample return mission, and will also include a rover.

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Lucy to fly past Earth on October 16th

10:13 am

Lucy solar panel graphic
Artist’s impression of solar panel

As part of its planned route to get to the Trojan asteroids in Jupiter’s orbit, the planetary probe Lucy is scheduled to fly only 220 miles above the Earth’s surface on October 16th.

Lucy will be passing the Earth at such a low altitude that the team had to include the effect of atmospheric drag when designing this flyby. Lucy’s large solar arrays increase this effect.

“In the original plan, Lucy was actually going to pass about 30 miles closer to the Earth,” says Rich Burns, Lucy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “However, when it became clear that we might have to execute this flyby with one of the solar arrays unlatched, we chose to use a bit of our fuel reserves so that the spacecraft passes the Earth at a slightly higher altitude, reducing the disturbance from the atmospheric drag on the spacecraft’s solar arrays.”

That solar array remains unlatched (as shown in the graphic above), but because it is almost completely deployed and is producing about 90% of its intended electricity, engineers have ceased efforts to complete deployment and latching.

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Final decision: Arecibo will not be rebuilt

3:34 pm

The National Science Foundation has made it official: It will not rebuild the Arecibo Observatory in Puerto Rico, though it will fund the facility as an education center instead.

Now, the National Science Foundation (NSF), which owns the site, has determined that despite scientists’ pleas, Arecibo Observatory won’t be getting any new telescope to replace the loss. The new education project also doesn’t include any long-term funding for the instruments that remain operational at the observatory, including a 40-foot (12 m) radio dish and a lidar system.

…Instead, the NSF intends to build on the observatory’s legacy as a key educational institution in Puerto Rico by transforming the site into a hub for science, technology, engineering and math (STEM) education, due to open in 2023, according to a statement. The observatory is also home to the Ángel Ramos Foundation Science and Visitor Center, which opened in 1997.

It seems unclear how this education center will function. Will it be a school that students attend? Or simply a type of museum with a visitors center? This new plan appears to call for about $2 million per year in funding, which does not appear enough to do much of anything, other than to keep the lights on and hang some pretty astronomy pictures on the walls.

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Changing slope streaks on Mars

3:08 pm

Overview map

Changing slope streaks on Mars
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on July 20, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows what the scientists have labeled a “Splitting Slope Streak” on a mound/hill near the equator and located almost midpoint between the giant volcano Olympus Mons about 2,000 miles to the east and the almost as big volcano Elysium Mons about 2,500 miles to the west. The white cross on the overview map above marks this location, north of the Medusae Fossae volcanic ash deposit.

The slope streak in question is the biggest and darkest at about 7 o’clock. Slope streaks are a feature unique to Mars that remain as yet unexplained. They are not ordinary avalanches, despite their appearance. They seem to have no effect on the topography, and thus are more a stain on the surface. Moreover, some are bright, some dark, and all happen randomly and fade with time. Some think they may be brine-related, while others link them to dust. No theory explains them completely.

What makes this slope streak interesting is that it is relatively new. Compare it with the picture taken in 2016 below.
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The known near Earth asteroid catalog now tops 30,000

9:35 am

Chart of NEA's discovered over time

The catalog of known near Earth asteroids that have been identified using a number of survey telescopes in space and on the Earth now totals 30,039. As defined at the link:

An asteroid is called a near-Earth asteroid (NEA) when its trajectory brings it within 1.3 Astronomical Units (au) of the Sun. 1 au is the distance between the Sun and Earth, and so NEAs can come within at least 0.3 au, 45 million km, of our planet’s orbit.

Currently, near-Earth asteroids make up about a third of the roughly one million asteroids discovered so far in the Solar System. Most of them reside in the asteroid belt between Jupiter and Mars.

NEAs are also called NEOs (Near Earth Objects). The chart above, produced by the Center for NEO Studies which tracks these objects, shows the number of NEAs discovered over time.

Of the 30,039 now known, about 1,400 have orbits with “a non-zero” chance of hitting the Earth. None however will do so in the next hundred years at least.

Though the pace of discovery is vastly improving — as indicated by the steep rise in the curve in the graph — only when that curve begins to flatten out will we know that we are getting close to having a more-or-less complete survey of these objects.

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