Looking at 1.7 billion stars


Click to enlargeESA/Gaia/DPAC

❝ Nearly 1.7 billion stars have been plotted in unprecedented detail with the highly anticipated release of data from the European Space Agency’s Gaia spacecraft.

The $1 billion (750 million euros) Gaia spacecraft launched in 2013 for a five-year mission to map the night sky with unmatched accuracy. The spacecraft is perched far beyond the moon’s orbit, in the Lagrange-2, or L2, point, a gravitationally stable spot about 1 million miles (1.5 million kilometers) away from Earth. Unlike space telescopes such as Hubble that orbit the Earth, Gaia can scan the cosmos without Earth blocking a large chunk of its view. As it rotates in space, Gaia measures about 100,000 stars each minute and covers the whole sky in about two months. Each star is measured 70 times on average. The new 3D map, which was unveiled here at the ILA Berlin Air Show, offers the best-ever look at the Milky Way — now in color — and promises to unleash hundreds of scientific discoveries about our galactic home and beyond…

The link above isn’t for the smaller 3D map. There is a link to that in the article. But, the link up top takes you to a 58+mb hi-res star map that opens to 8000×4000 pixels on two-clicks.

❝ The $1 billion Gaia spacecraft launched in 2013 for a five-year mission to map the night sky with unmatched accuracy. The spacecraft is perched far beyond the moon’s orbit, in the Lagrange-2, or L2, point, a gravitationally stable spot about 1 million miles away from Earth. Unlike space telescopes such as Hubble that orbit the Earth, Gaia can scan the cosmos without Earth blocking a large chunk of its view. As it rotates in space, Gaia measures about 100,000 stars each minute and covers the whole sky in about two months. Each star is measured 70 times on average.

Wow! Folks alive in that most-likely-distant future with faster-than-light travel going to have some fabulous vacations.

Greenland and the amazing technicolor coastline


Click to enlarge

Greenland’s coast has never looked so vibrant, thanks to this three-image fusion from the ESA’s Sentinel-1A radar. Shades of grey represent land, while colors illustrate the changing sea-ice type over the course of two months.

For now, the Zachariae Isstrom glacier sits slightly left of the image center, but it’s been shedding five billion tons of ice every year because of climate change. Should it disappear completely, global sea level would rise by more than 1.5 feet.

Couple more excellent space photos over here.

Did you ever realize how bad a comet smells?

Researchers describe the scent coming off 67P/Churyumov-Gerasimenko as reminiscent of rotten eggs and a horse stable.

They had outfitted Rosetta with a sort of artificial nose — an instrument called ROSINA — that can analyze gas vapors and replicate smell. Among other trace chemicals, Chury offers a powerful punch of hydrogen sulfide, ammonia, formaldehyde and hydrogen cyanide.

The strong presence of rotten egg (hydrogen sulfide) and horse stable (ammonia) smells are accented by notes of alcohol (methane) and vinegar (sulfur dioxide). In case that wasn’t gross enough, the hyrdogen cyanide and carbon disulfide offer a hint of sugared almonds.

Researchers say it’s the first time they’ve really gotten a good whiff of a comet.

“We’ve never been that close to a comet,” Kathrin Altwegg, the researcher who manages the ROSINA instrument from a lab at the University of Bern in Switzerland…

The comet — which Rosetta tried to anchor to with the exploratory craft called Philae — is 250 million miles from the sun. But it’s getting closer. And that’s bad news for astronomers with a weak stomach.

“The closer the comet gets to the sun, the more of its ice will evaporate, and the gas emissions will get more intense,” Altwegg explained to Deutsche Welle.

Sounds like the next time Earthlings sneak up on a comet and land on it to research its composition – we might include a little gas-powered engine in addition to solar panels to power the research vehicle. Something that runs on horse farts.

[Adapted from an article published just before Philae landed on 67P]

First landing on comet — photo history


Rosetta selfie with Comet 67/P in the background

History was made yesterday as a spacecraft the size of a fridge executed the first successful landing on a comet. The European Space Agency confirms that at about 16:00 GMT the unmanned Philae space probe touched down on the surface of comet 67P/Churyumov-Gerasimenko at the landing site known as Agilkia. The comet and spacecraft are 510 million km from Earth, so the news of the landing took 28 minutes and 20 seconds to reach mission control in Darmstadt, Germany.

The day before the landing, the 100 kg Phiale was turned on and its batteries charged for the first time since leaving Earth. There were some initial glitches as the batteries warmed more slowly than anticipated, but the spacecraft soon warmed up to its operational temperature. As the Rosetta mothership carrying Philae maneuvered into position, mission control carried out flight checks on the two spacecraft, sent command updates to Philae that allowed it to navigate autonomously to the landing site, and cleared the landing maneuver after a series of go/no decisions with the lander declared ready for separation at 02:35 GMT.

Despite a transient fault in the cold gas thruster aboard Philae, at 07:35 GMT Rosetta completed its final maneuver and the final permission was given to proceed with landing. At 09:03 Philae separated from Rosetta. During course correction maneuvers, communications with Earth were interrupted from either spacecraft, so they were programmed to operate autonomously…


First photo from Philae lander

…Since its arrival on August 6, the orbiter has been mapping the comet in search of a suitable landing site for the Philae lander.

…The landing…was based on a window where there would be enough sunlight to power the lander, but not so much as to make the comet dangerously active. Meanwhile, the site was chosen based on a balance between the scientific value of the area against the safety of the lander. Agilkia has very little slope, few boulders, and abundant sunlight, yet contains many features of interest.

ESA says that Philae has begun taking panoramic images as part of a two-and-a-half day science mission using its suite of 10 instruments, which could be extended if its solar panels are able to charge its batteries.

Bravo. Kudos to ESA for having the foresight and dedication to basic science and research required to fund and manage this project.

Click through to the article and more than 2 dozen photos from the history of the Rosetta project.

Thanks, Ursarodinia, Mike – GMTA

Comet close-ups from the Rosetta spacecraft

Following a decade-long meandering multi-loop de loop through the solar system, the European Space Agency’s (ESA) Rosetta spacecraft has finally reached its primary target: Comet 67P/Churyumov-Gerasimenko. What the comet lacks in a stylish name, it makes up for in historical prominence as it is the very first comet to get up close and personal with a manmade spacecraft…

Over the next few months, Rosetta will attempt to close in on a near-circular orbit of 30 km…before attempting to send a lander (dubbed” Philae”) onto the comet where it will take direct scientific measurements.

The Rosetta team has identified five possible landing sites on the comet and plans to settle on one by the middle of October, after which the agency will attempt to land the Philae lander in mid-November…

While the Rosetta mission will surely unlock a new understanding of our solar system, it has—more immediately—given us the privilege of being the very generation to see what a comet really looks like. Click through our slideshow of some of these spectacular images courtesy of the ESA.

As close as any of us are likely to get, folks. Take advantage of the photos.

Thanks, Mike

ESA’s shiny new Sentinel-1A satellite returns first Earth photos


Click to enlarge – Image of a transect across the northern section of the Antarctic Peninsula

ESA’s Sentinel-1A satellite has returned its first images of Earth from space in its second week of achieving orbit. The satellite, having been launched on Apr. 3. has only recently undergone a complicated maneuver to extend its 10 meter solar wings and 12 meter radar imaging array.

There are due to be six constellations of two Sentinel satellites designed to image the Earth, in part to observe climate change as a part of the Copernicus program. The satellite is not yet positioned in its operational orbit, nor is it fully calibrated to supply true data to the mission. However, the images taken on Apr. 12 are a truly stunning example of the observational capabilities of the cutting-edge satellite…

Over the next three months, the satellite will run through its commissioning phase, during which it will achieve operational orbit and be calibrated to begin what will be the most ambitious and largest Earth observation mission ever undertaken.

Lovely work. And much more knowledge to be gained about our planet.

If you have nothing else to worry about over the next few days…

Scientists say a 1-ton research satellite will crash to Earth in the next few days but they aren’t sure where.

The Gravity Field and Steady-State Ocean Circulation Explorer satellite will descend from an altitude of about 100 miles…

European Space Agency officials said when its about 50 miles above Earth, it will break apart and most of the pieces will burn up before they hit the ground Sunday or Monday.

A total of about 440 pounds of fragments of the satellite are expected to hit the ground.

“At present we can not say where the re-entry is going to happen except that it is not going to happen north of the 85 northern latitude or south of 85 southern latitude,” said Professor Heiner Klinkrad of the ESA.

“We are in contact with national civil protection agencies throughout Europe, of ESA member states, so they get all the information we have on the re-entry prediction and that also includes information on emergencies in case parts of the satellite fall on inhabited areas.”

So, if this piece of space junk lands on you – the appropriate civil authorities will know where to find your body. Whatever is left after impact. 🙂

Japan earthquake was heard at edge of space


Goce flies lower than any other scientific satellite

The great Tohoku earthquake in Japan two years ago was so big its effects were even felt at the edge of space.

Scientists say the Magnitude 9.0 tremor on 11 March 2011 sent a ripple of sound through the atmosphere that was picked up by the Goce satellite.

Its super-sensitive instrumentation was able to detect the disturbance as it passed through the thin wisps of air still present 255km above the Earth…

It has long been recognised that major quakes will generate very low-frequency acoustic waves, or infrasound – a type of deep rumble at frequencies below those discernible to the human ear. But no spacecraft in orbit has had the capability to record them, until now.

“We’ve looked for this signal before with other satellites and haven’t seen it, and I think that’s because you need an incredibly fine instrument,” said Dr Rune Floberghagen from the European Space Agency (ESA).

“Goce’s accelerometers are about a hundred times more sensitive than any previous instrumentation and we detected the acoustic wave not once, but twice – passing through it over the Pacific and over Europe,” the mission manager told BBC News.

Goce’s prime purpose is to map very subtle differences in the pull of gravity across the surface of the Earth caused by the uneven distribution of mass within the planet.

These variations produce almost imperceptible changes in the velocity of the satellite as it flies overhead and which it records with those high-precision accelerometers…

The Esa spacecraft encountered the signal as it passed over the Pacific some 30 minutes after the onset of the M9.0 event, and then again 25 minutes later as it moved across Europe.

Because of the way the accelerometers are arranged in Goce, it was possible to reconstruct the detection in three dimensions and so confidently trace the infrasound back to its source – the earthquake.

Stuff like this still astounds me. I’ve been reading works by science fiction writers for decades who described what was coming, what might yet be – but, it’s still difficult to get my brain around capabilities like this – as they become an ordinary part of our science lexicon.