Tag: aurora

The auroras of Jupiter and Ganymede

11:13 am

According to two different university press releases in the past month, new details have been discovered about the auroras found on Jupiter as well as its largest moon, Ganymede, caused by the interaction of Jupiter’s powerful magnetic field not only with Ganymede’s weak one but with the motion of all four Galilean moons as they orbit the gas giant.

The first study used data from Juno when it made a close fly-by of Ganymede in 2021. It not only showed how the aurora was caused by interaction between the magnetic fields of Jupiter and Ganymede, it found that Ganymede’s auroras were similar to those on Earth.

Similar structures, known as ‘beads’, have been observed in the auroras of Earth and Jupiter, where they are linked to sub-storms and dawn storms, large-scale rearrangements of the magnetosphere that release enormous amounts of energy and produce intense auroral activity,” explains Alessandro Moirano, post-doctoral researcher at LPAP.

Ganymede interacts with Jupiter’s space environment in a similar way to how Earth interacts with the solar wind; therefore, the discovery of auroral patches on Ganymede similar to those on Earth suggests that the fundamental physical process(es) could be generally induced in the coupling between any celestial body, its magnetosphere, and external forces.

The aurora's on Jupiter
The auroral footprints of Io and Europa
on Jupiter

The second study, released yesterday, used the Webb Space Telescope to a get a more detailed look at Jupiter’s auroras, caused as the four Galilean moons — Io, Europa, Ganymede, and Callisto — travel through Jupiter’s powerful magnetic field, causing energetic particles to following Jupiter’s magnetic field lines down to its poles, there creating the auroras.

Webb’s data found that the auroral footprints on Jupiter caused by each moon were different from Jupiter’s own aurora.

However, the footprints created by Io and Europa, did not have the characteristics expected from Jupiter’s main aurora, which contains a lot of hot material. Instead, in one snapshot, they discovered a cold spot within Io’s auroral footprint that registered temperatures much lower than expected, with extraordinarily high densities.

As the data was limited to a single 22-hour window, the results are very uncertain. More observations are planned, covering a longer time period, to see if this phenomenon can be captured again.

All of these results are very tantalizing, but to really get a handle on what is going on will require continuous observations over years, from many spacecraft devoted exclusively to Jupiter. And that isn’t going to happen for quite some time.

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Dawn Aerospace begins offering its suborbital spaceplane to customers

12:15 pm

Though the company has only so far flown a small prototype on low altitude supersonic test flights, the spaceplane startup Dawn Aerospace is now taking orders for those who wish to put payloads on its proposed Aurora suborbital spaceplane, targeting a first flight in late 2026.

Dawn Aerospace is taking orders now for the Aurora spaceplane for deliveries starting in 2027. The company has not disclosed pricing for the vehicle, and [CEA Stefan] Powell suggested the company would tailor pricing to each customer. He said that the company estimates, based on market research, that a per-flight price of $100,000 is “absolutely tenable,” and the price could go higher for missions with more customized flight needs. He projects Aurora could fly 100 times a year and has a design life of 1,000 flights, with a total revenue per vehicle of about $100 million.

Though the company had originally touted itself as developing an orbital spaceplane, it recently shifted its goals, at least for the present, to building a very powerful jet comparable in some ways to the X-15, capable of reaching altitudes exceeding 50 miles for short periods and short periods of weightlessness. This capability has some value, and Dawn Aerospace has decided to market it for profit, rather than wait for the orbital version that might be years away.

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NASA: Perseverance observed the first visible-light aurora in March 2024

10:15 am

According to a NASA/JPL press release today, Perseverance successfully observed the first visible-light aurora on another world when in March 2024 it photographed a faint aurora overhead, caused by a strong solar flare.

The images at the link are quite unexciting, so much so that I don’t see a reason to include it here. The aurora observed is barely noticeable. Moreover, this is not really a new discovery. Previous observations in the ultraviolet had determined that Mars does have a weak aurora. That in rare circumstances a strong solar event can have it also appear in visible wavelengths is hardly news.

Normally I would have considered this story unimportant enough to list merely as a quick link at the end of the day, but I post it now because of how the mainstream propaganda press has latched onto it as if it is a big deal. The New York Times, the Washington Post, and the Associated Press all posted stories, giving it far more play than it deserves.

My impression from all these articles is that their reporters know almost nothing about Mars and the research that is going on there, and were easily bamboozled by the press people at NASA and JPL to report this relatively minor story loudly. They no longer have anyone who covers science and space on a regular basis and thus understand the larger context, so therefore their coverage is often shaped entirely by the public relations departments at NASA.

More proof that in today’s internet world, if you want good information the last place you should go is the old dinosaur press.

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Webb images in the infrared the aurora of Neptune

9:30 am

The aurora of Neptune
Click for original image.

Astronomers using the Webb Space Telescope have captured the first infrared images of the aurora of Neptune, confirming that the gas giant produces this phenomenon.

The picture to the right combines infrared data from Webb and optical imagery from the Hubble Space Telescope. The white splotches near the bottom of the globe are clouds seen by Hubble. The additional white areas in the center and near the top are clouds detected by Webb, while the greenish regions to the right are aurora activity detected by Webb.

The auroral activity seen on Neptune is also noticeably different from what we are accustomed to seeing here on Earth, or even Jupiter or Saturn. Instead of being confined to the planet’s northern and southern poles, Neptune’s auroras are located at the planet’s geographic mid-latitudes — think where South America is located on Earth.

This is due to the strange nature of Neptune’s magnetic field, originally discovered by Voyager 2 in 1989, which is tilted by 47 degrees from the planet’s rotation axis. Since auroral activity is based where the magnetic fields converge into the planet’s atmosphere, Neptune’s auroras are far from its rotational poles.

The data also found that the temperature of Neptune’s upper atmosphere has cooled significantly since it was first measured by Voyager 2 in 1989, dropping by several hundred degrees.

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Polaris Spaceplanes wins contract to develop “a fully reusable hypersonic research vehicle”

9:50 am

The European startup Polaris Spaceplanes, which has been doing tests of an aerospike engine for use in its proposed Aurora orbital re-usable spaceplane, has now won a contract from the German military to develop “a fully reusable hypersonic research vehicle”.

The contract describes the vehicle as a hypersonic testbed and experimental platform for defence-related applications, as well as scientific and institutional research. A secondary role of the vehicle will be to serve as a small satellite launch system when equipped with an expendable upper stage.

While not directly named in the update, this contract will likely kick off the development of AURORA. The contract’s initial scope is limited to the design of the vehicle. However, POLARIS revealed that the contract also includes provisions for follow-on initiatives to manufacture and flight-test the full-size vehicle.

The company has also done a series of test flights using smaller engineering test vehicles. It appears these tests convinced the German military to issue the company this contract.

This contract award also underlines Germany’s enthusiastic embrace of capitalism in space. It not only encouraged the establishment of the most rocket startups ahead of any other European nation, it is now taking action to encourage other aerospace startups as well.

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Polaris completes first inflight ignition of its aerospike engine

12:08 am

In what appears to be a first, Polaris Spaceplane on October 29, 2024 successfully completed the first ever inflight ignition of an aerospike engine, using its Mira-2 unmanned engineering prototype.

Later in the day on 29 October, MIRA II took off from Peenemünde Airport on the coast of the Baltic Sea with a takeoff mass of 229 kilograms, which represented a reduced propellant load. The vehicle flew to the ignition point over the Baltic Sea, approximately 3 kilometres away from the ground station, and once there, completed a short three-second burn of its AS-1 aerospike engine. During the short burn, MIRA II experienced an acceleration of 4 m/s².

According to the company, the engine operated at a reduced chamber pressure during the three-second burn, resulting in a fuel-rich combustion.

There have been several attempts in the past to develop the aerospike engine, none of which ever completed any test flights, as far as I am aware. The concept is that the thrust is released in a string of openings, with only one wall forming the nozzle shape and the atmosphere used to complete the nozzle on the other side. As the atmospheric density changes the nozzle shape thus changes its shape, producing the most efficient thrust throughout the engine’s entire flight.

More test flights will be required before the company will be able to begin work on its full scale Aurora spaceplane.

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Polaris Spaceplanes begins test flights of its second Mira prototype

9:42 am

After losing its first Mira prototype test plane during a flight in May, the German startup Polaris Spaceplanes has now begun test flights of its replacement, dubbed Mira-2.

With this prototype the company hopes to test its aerospike engine in flight for the first time, leading to the construction of its full scale spaceplane Aurora.

This five-metre-long vehicle is equipped with jet engines for take-off and landing and one of the company’s in-house developed AS-1 aerospike engines for rocket-powered flight.

POLARIS conducted the first three test flights of the MIRA II demonstrator at the Peenemünde Airport on the coast of the Baltic Sea. Over the three flights, the vehicle accumulated a total of 20 minutes of flight time and covered more than 50 kilometres.

All three flights were unmanned, as Mira-2 is relatively small. The company will now install the aerospike engine, with the next flights testing that engine. If successful, it would be the first time ever an aerospike rocket engine has ever flown.

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Solar storms are simply no longer a threat

3:39 pm

The sunspot cycle as of May 2024
The sunspot cycle as of May 2024. Click
for full details.

Today’s Chicken Little Report: When NOAA predicted on May 9, 2024 that a powerful solar flare had erupted from the Sun and was aiming a major solar storm directly at the Earth, the scientists at the federal government’s Space Weather Prediction Center could not help underlining the disaster potential, and were ably aided by the mainstream press. This CNN report was typical:

“Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting communications, the electric power grid, navigation, radio and satellite operations,” according to the Space Weather Prediction Center. “(The center) has notified the operators of these systems so they can take protective action.”

The center has notified operators in these areas to take action to mitigate the potential for any impacts, which include the possibility of increased and more frequent voltage control problems. Other aspects operators will monitor include a chance of anomalies or impacts to satellite operations and frequent or longer periods of GPS degradation.

And as always, the news report has to end with this warning of doom:
» Read more

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The aurora as seen looking down from space

9:12 am

The aurora over the U.S. on May 11, 2024
Click for original image.

NOAA on May 13, 2024 released a set of eight images taken by its fleet of JPSS weather satellites, showing the strong Aurora Borealis or Northern Lights that were activated over the May 11th weekend due to several very strong solar flares on the Sun and sent a geomagnetic storm at the Earth.

One of those images, reduced to post here, is to the right. You can see the eastern coast of the United States, outlined by city lights, with a band of aurora cutting across the northern half and reaching south below the Great Lakes. The other seven images are available at the link above.

The geomagnetic storm was the strongest produced by the Sun in more than two decades, since 2003. That storm occurred during solar maximum, as did the May 11th this past weekend. However, the Sun experienced another solar maximum in-between, in 2014, which produced few such storms, and none as strong.

I want to add that despite the screams of panic prior to the arrival of this storm, its arrival produced only minor disturbances in the world’s electrical grid, and in fact was proof positive that the many decades of work that electrical companies have devoted to protecting the grid from such storms has paid off. It is very unlikely any major storm from the Sun can harm that grid in the future, unless of course we get lazy and stop maintaining it.

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German space plane company completes test program of prototype

10:37 am

The German space plane company Polaris Spaceplanes had now completed a 15-flight test program of the small prototype of its planned orbital and suborbital spaceplane.

The test-flights took place over the course of three days, between Aug. 22 and Sep. 8, and were meant to demonstrate the vehicle’s aerodynamics and flight control systems in preparation for a larger-scale spaceplane prototype the company plans to equip with a linear aerospike rocket engine.

MIRA-Light measures just 8.2 feet (2.5 meters) long, and flies using four electric fans. For 10 of MIRA-Light’s 15 flights, the mini-spaceplane was equipped with a mock aerospike engine to simulate its impact on vehicle performance. In total, the prototype accumulated about 40 total minutes of flight time, according to a report from European Spaceflight.

What makes this project interesting is its use of an aerospike engine, a rocket-engine concept that has been around for decades but never successfully implemented. If successful here, it will make the engines of Polaris’ spaceplane very efficient.

The company now plans a series of test programs using prototypes of increasing size, leading to flying its full-scale hypersonic space plane Aurora on commercial suborbital and orbital flights in ’26 or ’27.

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Martian auroras as seen by UAE’s Al-Amal orbiter

10:42 am

Aurora types on Mars
Click for full image.

Using data gathered by the Al-Amal orbiter (“Hope” in English), scientists have identified three types of aurora on Mars. The image to the right, figure 1 from their paper, shows these types, crustal field aurora, patchy aurora, and sinuous aurora. From the abstract:

We categorize discrete auroral patterns into three types: those near strong vertical crustal magnetic field, patchy aurora near very weak crustal fields, and a new type we call “sinuous,” an elongated serpentine structure that stretches thousands of kilometers into the nightside from near midnight in the northern hemisphere.

All three types generally occur during the Martian night, and evolve quickly over periods of less than 45 minutes. The first type, which is generally the brightest, forms over terrain where Mars’ residual magnetic field is strongest and vertically oriented, and was most often seen over the southern cratered highlands centered between the large impact basins Argyre and Hellas. The third type, sinuous aurora, was more unusual:

These we are calling “sinuous discrete aurora,” due to their thin, elongated, and sometimes serpentine shapes. They share several key traits: (a) they appear in the northern hemisphere away from strong crustal fields, (b) they usually connect to the dayside in the far north but also sometimes separately at lower latitudes, (c) they extend for thousands of kilometers into the night side, (d) they appear on both dusk and dawn sides, and (e) their shapes change moderately and brightnesses shift by factors of up to two over timescales of ∼20 min (i.e., the time between swaths, as shown in the differences between Figures 1j and 1k [in the figure above).

The existence of aurora on Mars has been known since the 2000s. These observations however are the first that show more details beyond a fuzzy patch.

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Virgin Galactic is replacing its WhiteKnightTwo mother ship

9:21 am

Virgin Galactic yesterday announced that it has hired Aurora, a Boeing subsidiary, to build two new mother ships to to replace WhiteKnightTwo and launch its SpaceShipTwo suborbital space planes.

Virgin Galactic Chief Executive Officer Michael Colglazier said: “Our next generation motherships are integral to scaling our operations. They will be faster to produce, easier to maintain and will allow us to fly substantially more missions each year. Supported by the scale and strength of Boeing, Aurora is the ideal manufacturing partner for us as we build our fleet to support 400 flights per year at Spaceport America.” [emphasis mine]

The press release claims the first new mother ship will begin operations in 2025.

Forgive me if I am very very skeptical. The highlighted words tell us a lot about this company. First, we now have confirmation that the company has had problems maintaining WhiteKnightTwo. This fact was strongly implied when all planned flights in ’21 and ’22 were cancelled following that first passenger flight in July ’21 in order to do a full maintenance refit of WhiteKnightTwo. This press release tells us that the company’s management has recognized that WhiteKnightTwo cannot be maintained much longer.

Second, the company continues to overhype its future, even without Richard Branson. The chances of it flying 400 times per year, anytime in the near future, is so slim as to be non-existent.

Third, the need to hire an outside company to build these new mother ships also suggests that Virgin Galactic no longer has the capability of doing it itself.

Right now the company’s stock is selling for about $7 per share, well below its initial price of about $12. Expect it to fall again.

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Al-Amal detects Martian aurora

10:11 am

Aurora on Mars

The United Arab Emirates Al-Amal Mars orbiter has detected evidence of a Martian aurora that would be visible at night for short periods.

The ultraviolet images to the right have been reduced slightly to post here.

These three images of atomic oxygen emission at a wavelength of 103.4 nm from the planet Mars were obtained by the Emirates Mars Ultraviolet Spectrometer instrument on 22 April, 23 April, and 06 May 2021 respectively. The full set of data collected during these observations include far and extreme ultraviolet auroral emissions which have never been imaged before at Mars. The beacons of light that stand out against the dark nightside disk are highly structured discrete aurora, which traces out where energetic particles excite the atmosphere after being funneled down by a patchy network of crustal magnetic fields that originate from minerals on the surface of Mars.

Though Mars does not have a magnetic field, it is believed that sections of the planet’s crust are magnetized, and under the right conditions can guide the charged particles from the Sun’s solar wind to the night side to hit the atmosphere where they break up and produce the aurora. Because there is no magnetic field however the particles are not guided by the field lines to the poles, but to different spots at all latitudes, depending on circumstances.

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The aurora of Saturn

10:11 am

Cool movie time! Using the Hubble space telescope scientists have compiled an animation showing the changes in Saturn’s north pole aurora over time.

In 2017, over a period of seven months, the NASA/ESA Hubble Space Telescope took images of auroras above Saturn’s north pole region using the Space Telescope Imaging Spectrograph. The observations were taken before and after the Saturnian northern summer solstice. These conditions provided the best achievable viewing of the northern auroral region for Hubble.

…The images show a rich variety of emissions with highly variable localized features. The variability of the auroras is influenced by both the solar wind and the rapid rotation of Saturn, which lasts only about 11 hours. On top of this, the northern aurora displays two distinct peaks in brightness — at dawn and just before midnight. The latter peak, unreported before, seems specific to the interaction of the solar wind with the magnetosphere at Saturn’s solstice.

The animation of all the images is embedded below. At the link is a second video showing the aurora in close-up

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Solar storm activates global aurora on Mars

12:00 pm

The strong solar flare that occurred earlier this month was strong enough to activate a global aurora on Mars.

The solar event on Sept. 11, 2017 sparked a global aurora at Mars more than 25 times brighter than any previously seen by the MAVEN orbiter, which has been studying the Martian atmosphere’s interaction with the solar wind since 2014. It produced radiation levels on the surface more than double any previously measured by the Curiosity rover’s Radiation Assessment Detector, or RAD, since that mission’s landing in 2012. The high readings lasted more than two days.

Strangely, it occurred in conjunction with a spate of solar activity during what is usually a quiet period in the Sun’s 11-year sunspot and storm-activity cycle. This event was big enough to be detected at Earth too, even though Earth was on the opposite side of the Sun from Mars.

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Hubble images Jupiter and its aurora

9:03 am

Jupiter and its aurora

Cool image time! In anticipation of the arrival of Juno in orbit around Jupiter on July 4, scientists have released a spectacular image of Jupiter and its aurora, taken by the Hubble Space Telescope. The image on the right has been reduced slightly to fit on the webpage.

The main focus of the imaging is the aurora.

To highlight changes in the auroras, Hubble is observing Jupiter almost daily for several months. Using this series of far-ultraviolet images from Hubble’s Space Telescope Imaging Spectrograph, it is possible for scientists to create videos that demonstrate the movement of the vivid auroras, which cover areas bigger than the Earth.

Not only are the auroras huge in size, they are also hundreds of times more energetic than auroras on Earth. And, unlike those on Earth, they never cease. While on Earth the most intense auroras are caused by solar storms — when charged particles rain down on the upper atmosphere, excite gases, and cause them to glow red, green, and purple — Jupiter has an additional source for its auroras.

The strong magnetic field of the gas giant grabs charged particles from its surroundings. This includes not only the charged particles within the solar wind, but also the particles thrown into space by its orbiting moon Io, known for its numerous and large volcanos.

I have embedded below the fold one of the videos of the aurora, taken over time by Hubble. Quite amazing.
» Read more

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The late arrival of Russia’s first private satellite

8:43 am

The competition heats up? The Dnepr rocket launch of 37 satellites yesterday also included the launch of the first private Russian satellite.

TabletSat-Aurura owned by the company SPUTNIX weighs 26.2 kg and is made to operate for one year. It is intended for remote Earth sensing in the interests of a private company. The satellite was made using Russian technologies and a minimum of foreign components. Its cost is about one million US dollars.

Igor Komarov, the head of the United Rocket and Space Corporation, said “the launch of Aurora, the first Russian private satellite, is a successful example of public-private partnership in the field of space exploration as private companies clearly cannot fulfill their strategic tasks without the state. ,,, I am confident that cooperation between the state and private aerospace agencies in designing and manufacturing high-tech craft will become an important stimulus for further development of Russian competitive technologies.”

SPUTNIX Director-General Andrei Potapov said his company’s plans included “creating a cluster of small spacecraft and craft for super high-definition aerial video surveying and imaging with a resolution of down to one meter per pixel”. [emphasis mine]

Why do I have doubts about this Russian achievement? The reasons are twofold.
» Read more

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Commemorating the victims in Colorado.

9:49 pm

Commemorating the victims in Colorado.

I don’t normally report on these violent events. However, I think Malkin’s point here is valid. Too much press has been given the mass murderer in this crime, and not enough for his innocent victims. And in order to understand the truly evil nature of this crime, it is important to know the kind of people this horrible man calmly killed. For example, “6-year-old Veronica Moser identified as Aurora shooting victim; mom in critical condition.”

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The biggest solar storm to be aimed at the Earth in seven years is expected to reach us by Tuesday.

1:57 pm

The biggest coronal mass ejection to be aimed at the Earth in seven years is expected to reach us by Tuesday.

No need to panic. Not only is the storm still relatively mild compared to past eruptions, the airline and electrical industries are actually well prepared for this event. However, if you want to see the aurora, this will probably be a good opportunity.

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