Weekly Space Hangout – October 21, 2016: Dr. Voula Saridakis of @histastro & Morgan is a Tilted Sun

Host: Fraser Cain (@fcain)

Special Guest:
This week’s special guest is Dr. Voula Saridakis, a professor at Lake Forest College in Illinois specializing in the history of science and astronomy, who runsthe History of Astronomy on Twitter at @histastro

Guests:
Morgan Rehnberg (MorganRehnberg.com / @MorganRehnberg)
Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )
Alessondra Springmann (sondy.com / @sondy)
Nicole Gugliucci (cosmoquest.org / @noisyastronomer)

Their stories this week:

Schiaparelli /TGO
The Unexpected Detection of Dark Matter Galaxies
News from DPS:
Planet 9
Juno
Exomars
Comet 67p

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

If you would like to sign up for the AstronomyCast Solar Eclipse Escape, where you can meet Fraser and Pamela, plus WSH Crew and other fans, visit our site linked above and sign up!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page.

Journey’s End: Comet Crash for Rosetta Mission Finale

With a soft “awwww” from the mission team in the control center in Darmstadt, Germany, the signal from the Rosetta spacecraft faded, indicating the end of its journey. Rosetta made a controlled impact onto Comet 67P/Churyumov–Gerasimenko, sending back incredible close-up images during descent, after two years of investigations at the comet.

“Farewell Rosetta. You have done the job. That was space science at its best,” said Patrick Martin, Rosetta mission manager.

Rosetta’s final resting spot appears to be in a region of active pits in the Ma’at region on the two-lobed, duck-shaped comet.

The information collected during the descent – as well as during the entire mission – will be studied for years. So even though the video below about the mission’s end will likely bring a tear to your eye, rest assured the mission will continue as the science from Rosetta is just getting started.

“Rosetta has entered the history books once again,” says Johann-Dietrich Wörner, ESA’s Director General. “Today we celebrate the success of a game-changing mission, one that has surpassed all our dreams and expectations, and one that continues ESA’s legacy of ‘firsts’ at comets.”

Launched in 2004, Rosetta traveled nearly 8 billion kilometers and its journey included three Earth flybys and one at Mars, and two asteroid encounters. It arrived at the comet in August 2014 after being in hibernation for 31 months.

After becoming the first spacecraft to orbit a comet, it deployed the Philae lander in November 2014. Philae sent back data for a few days before succumbing to a power loss after it unfortunately landed in a crevice and its solar panels couldn’t receive sunlight. But Rosetta continued to monitor the comet’s evolution as it made its closest approach and then moved away from the Sun. However, now Rosetta and the comet are too far away from the Sun for the spacecraft to receive enough power to continue operations.

“We’ve operated in the harsh environment of the comet for 786 days, made a number of dramatic flybys close to its surface, survived several unexpected outbursts from the comet, and recovered from two spacecraft ‘safe modes’,” said operations manager Sylvain Lodiot. “The operations in this final phase have challenged us more than ever before, but it’s a fitting end to Rosetta’s incredible adventure to follow its lander down to the comet.”

Compilation of the brightest outbursts seen at Comet 67P/Churyumov–Gerasimenko by Rosetta’s OSIRIS narrow-angle camera and Navigation Camera between July and September 2015. Credit: OSIRIS: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; NavCam: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0.
Compilation of the brightest outbursts seen at Comet 67P/Churyumov–Gerasimenko by Rosetta’s OSIRIS narrow-angle camera and Navigation Camera between July and September 2015. Credit: OSIRIS: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; NavCam: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0.

Rosetta’s Legacy and Discoveries

Of its many discoveries, Rosetta’s close-up views of the curiously-shaped Comet 67P have already changed some long-held ideas about comets. With the discovery of water with a different ‘flavor’ to that of Earth’s oceans, it appears that Earth impacts of comets like 67P/Churyumov–Gerasimenko may not have delivered as much of Earth’s water as previously thought.

From Philae, it was determined that even though organic molecules exist on the comet, they might not be the kind that can deliver the chemical prerequisites for life. However, a later study revealed that complex organic molecules exist in the dust surrounding the comet, such as the amino acid glycine, which is commonly found in proteins, and phosphorus, a key component of DNA and cell membranes. This reinforces the idea that the basic building blocks may have been delivered to Earth from an early bombardment of comets.

Rosetta’s long-term monitoring has also shown just how important the comet’s shape is in influencing its seasons, in moving dust across its surface, and in explaining the variations measured in the density and composition of the comet’s coma.

And because of Rosetta’s proximity to the comet, we all went along for the ride as the spacecraft captured views of what happens as a comet comes close to the Sun, with ice sublimating and dusty jets exploding from the surface.

Studies of the comet show it formed in a very cold region of the protoplanetary nebula when the Solar System was forming more than 4.5 billion years ago. The comet’s two lobes likely formed independently, but came together later in a low-speed collision.

“Just as the Rosetta Stone after which this mission was named was pivotal in understanding ancient language and history, the vast treasure trove of Rosetta spacecraft data is changing our view on how comets and the Solar System formed,” said project scientist Matt Taylor.

Sequence of images captured by Rosetta during its descent to the surface of Comet 67P/C-G on September 30, 2016. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.
Sequence of images captured by Rosetta during its descent to the surface of Comet 67P/C-G on September 30, 2016. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Journey’s End

During the final hours of the mission on Friday morning, the instrument teams watched the data stream in and followed the spacecraft as it moved closer to its targeted touchdown location on the “head” of the 4km-wide comet. The pitted region where Rosetta landed appear to be the places where 67P ejects gas and dust into space, and so Rosetta’s swan song will provide more insight into the comet’s icy jets.

“With the decision to take Rosetta down to the comet’s surface, we boosted the scientific return of the mission through this last, once-in-a-lifetime operation,” said Martin. ““It’s a bittersweet ending, but … Rosetta’s destiny was set a long time ago. But its superb achievements will now remain for posterity and be used by the next generation of young scientists and engineers around the world.”

See more stunning, final images in Bob King’s compilation article, and we bid Rosetta farewell with this lovely poem written by astropoet Stuart Atkinson (used here by permission).

Rosetta’s Last Letter Home

By Stuart Atkinson

And so, my final day dawns.
Just a few grains are left to drain through
The hourglass of my life.
The Comet is a hole in the sky.
Rolling, turning, a black void churning
Silently beneath me.
Down there, waiting for me, Philae sleeps,
Its bed a cold cave floor,
A quilt of sparkling hoarfrost
Pulled over its head…

I have so little time left;
I sense Death flying behind me,
I feel his breath on my back as I look down
At Ma’at, its pits as black as tar,
A skulls’s empty eye sockets staring back
At me, daring me to leave the safety
Of this dusty sky and fly down to join them,
Never to spread my wings again; never
To soar over The Comet’s tortured pinnacles and peaks,
Or play hide and seek in its jets and plumes…

I don’t want to go.
I don’t want to be buried beneath that filthy snow.
This is wrong! I want to fly on!
There is so much more for me to see,
So much more to do –
But the end is coming soon.
All I ask of you is this: don’t let me crash.
Help me land softly, kissing the ground,
Coming to rest with barely a sound
Like a leaf falling from a tree.
Don’t let me die cartwheeling across the plain,
Wings snapping, cameras shattering,
Pieces of me scattering like shrapnel
Across the ice. Let me end my mayfly life
In peace, whole, not as debris rolling uncontrollably
Into Deir el-Medina…

It’s time to go, I know.
Only hours remain until I join Philae
And my great adventure ends
So I’ll send this and say goodbye.
If I dream, I’ll dream of Earth
Turning beneath me, bathing me in
Fifty shades of blue…
In years to come I hope you’ll think of me
And smile, remembering how, for just a while,
We explored a wonderland of ice and dust
Together, hand in hand.

(c) Stuart Atkinson 2016

Carnival of Space #468-469

Carnival of Space. Image by Jason Major.

Welcome, come in to the 468th and 469th Carnival of Space – we combined these two since it’s summer break for a lot of folks!  The Carnival is a community of space science and astronomy writers and bloggers, who submit their best work each week for your benefit. I’m Susie Murph, part of the team at Universe Today and CosmoQuest. So now, on to this week’s stories!
Continue reading “Carnival of Space #468-469”

Spectacular Celestial Fireworks Commemorate Perihelion Passage of Rosetta’s Comet

Sequence of OSIRIS narrow-angle camera images from 12 August 2015, just a few hours before the comet reached perihelion. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
See hi res images below[/caption]

A spectacular display of celestial fireworks like none ever witnessed before, burst forth from Rosetta’s comet right on time – commemorating the Europeans spacecraft’s history making perihelion passage after a year long wait of mounting excitement and breathtaking science.

As the European Space Agency’s (ESA’s) Rosetta marked its closest approach to the Sun (perihelion) at exactly 02:03 GMT on Thursday, August 13, 2015, while orbiting Comet 67P/Churyumov–Gerasimenko, its suite of 11 state-of-the-art science instruments, cameras and spectrometers were trained on the utterly bizarre bi-lobed body to capture every facet of the comet’s nature and environment for analysis by the gushing science teams.

And the perihelion passage did not disappoint – living up to its advance billing by spewing forth an unmatched display of otherworldly outbursts of gas jets and dust particles due to surface heating from the warming effects of the sun as the comet edged ever closer, coming within 186 million kilometers of mighty Sol.

ESA has released a brand new series of images, shown above and below, documenting sparks flying – as seen by Rosetta’s OSIRIS narrow-angle camera and NAVCAM wider angle cameras on August 12 and 13 – just a few hours before the rubby ducky shaped comet reached perihelion along its 6.5-year orbit around the sun.

Images of Comet 67P/C-G taken with OSIRIS narrow-angle camera on 12 August 2015, just a few hours before the comet reached perihelion, about 330 km from the comet. The individual images are also available below. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Images of Comet 67P/C-G taken with OSIRIS narrow-angle camera on 12 August 2015, just a few hours before the comet reached perihelion, about 330 km from the comet. The individual images are also available below. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Indeed the navcam camera image below was taken just an hour before the moment of perihelion, at 01:04 GMT, from a distance of around 327 kilometers!

Frozen ices are seen blasting away from the comet in a hail of gas and dust particles as rising solar radiation heats the nucleus and fortifies the comet’s atmosphere, or coma, and its tail.

Comet at perihelion.  Single frame Rosetta navigation camera image acquired at 01:04 GMT on 13 August 2015, just one hour before Comet 67P/Churyumov–Gerasimenko reached perihelion – the closest point to the Sun along its 6.5-year orbit. The image was taken around 327 km from the comet. It has a resolution of 28 m/pixel, measures 28.6 km across and was processed to bring out the details of the comet's activity. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Comet at perihelion. Single frame Rosetta navigation camera image acquired at 01:04 GMT on 13 August 2015, just one hour before Comet 67P/Churyumov–Gerasimenko reached perihelion – the closest point to the Sun along its 6.5-year orbit. The image was taken around 327 km from the comet. It has a resolution of 28 m/pixel, measures 28.6 km across and was processed to bring out the details of the comet’s activity. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

After a decade long chase of over 6.4 billion kilometers (4 Billion miles), ESA’s Rosetta spacecraft arrived at the pockmarked Comet 67P/Churyumov-Gerasimenko exactly a year ago on Aug. 6, 2014 for history’s first ever attempt to orbit a comet for long term study.

In the interim, Rosetta also deployed the piggybacked Philae lander for history’s first landing on a comet on Nov. 12, 2014.

In fact, measurements from Rosetta’s science instruments confirm the comet is belching a thousand times more water vapor today than was observed during Rosetta’s arrival a year ago. It’s spewing some 300 kg of water vapour every second now, compared to just 300 g per second upon arrival. That equates to two bathtubs per second now in Aug. 2015 vs. two small glasses of water per second in Aug. 2014.

Besides gas, 1000 kg of dust per second is simultaneously erupting from the nucleus, “creating dangerous working conditions for Rosetta,” says ESA.

“In recent days, we have been forced to move even further away from the comet. We’re currently at a distance of between 325 km and 340 km this week, in a region where Rosetta’s startrackers can operate without being confused by excessive dust levels – without them working properly, Rosetta can’t position itself in space,” comments Sylvain Lodiot, ESA’s spacecraft operations manager, in an ESA statement.

Here’s an OSIRIS image taken just hours prior to perihelion, that’s included in the lead animation of this story.

OSIRIS NAC image of Comet 67P/C-G taken on 12 August 2015 at 17:35 GMT. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
OSIRIS NAC image of Comet 67P/C-G taken on 12 August 2015 at 17:35 GMT. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The period of the comet’s peak intensity, as seen in all these images, is expected to continue past perihelion for several weeks at least and fulfils the dreams of a scientific goldmine for all the research teams and hundreds of researchers involved with Rosetta and Philae.

“Activity will remain high like this for many weeks, and we’re certainly looking forward to seeing how many more jets and outburst events we catch in the act, as we have already witnessed in the last few weeks,” says Nicolas Altobelli, acting Rosetta project scientist.

And Rosetta still has lots of fuel, and just as important – funding – to plus up its ground breaking science discoveries.

ESA recently granted Rosetta a 9 month mission extension to continue its research activities as well as having been given the chance to accomplish one final and daring historic challenge.

Engineers will attempt to boldly go and land the probe on the undulating surface of the comet.

Officials with the European Space Agency (ESA) gave the “GO” on June 23 saying “The adventure continues” for Rosetta to march forward with mission operations until the end of September 2016.

If all continues to go well “the spacecraft will most likely be landed on the surface of Comet 67P/Churyumov-Gerasimenko” said ESA.

ESA Philae lander approaches comet 67P/Churyumov–Gerasimenko on 12 November 2014 as imaged from Rosetta orbiter after deployment and during seven hour long approach for 1st ever  touchdown on a comets surface.  Credit:  ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA - Composition by Marco Di Lorenzo/Ken Kremer
ESA Philae lander approaches comet 67P/Churyumov–Gerasimenko on 12 November 2014 as imaged from Rosetta orbiter after deployment and during seven hour long approach for 1st ever touchdown on a comets surface. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA – Composition by Marco Di Lorenzo/Ken Kremer

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com
Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com

Rosetta Orbiter Approved for Extended Mission and Bold Comet Landing

Rosetta will attempt comet landing
This single frame Rosetta navigation camera image of Comet 67P/Churyumov-Gerasimenko was taken on 15 June 2015 from a distance of 207 km from the comet centre. The image has a resolution of 17.7 m/pixel and measures 18.1 km across. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0 [/caption]

Europe’s history making Rosetta cometary spacecraft has been granted a nine month mission extension to plus up its bountiful science discoveries as well as been given the chance to accomplish one final and daring historic challenge, as engineers attempt to boldly go and land the probe on the undulating surface of the comet its currently orbiting.

Officials with the European Space Agency (ESA) gave the “GO” on June 23 saying “The adventure continues” for Rosetta to march forward with mission operations until the end of September 2016.

If all continues to go well “the spacecraft will most likely be landed on the surface of Comet 67P/Churyumov-Gerasimenko” said ESA to the unabashed glee of the scientists and engineers responsible for leading Rosetta and reaping the rewards of nearly a year of groundbreaking research since the probe arrived at comet 67P in August 2014.

“This is fantastic news for science,” says Matt Taylor, ESA’s Rosetta Project Scientist, in a statement.

It will take about 3 months for Rosetta to spiral down to the surface.

After a decade long chase of over 6.4 billion kilometers (4 Billion miles), ESA’s Rosetta spacecraft arrived at the pockmarked Comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014 for history’s first ever attempt to orbit a comet for long term study.

Since then, Rosetta deployed the piggybacked Philae landing craft to accomplish history’s first ever touchdown on a comets nucleus on November 12, 2014. It has also orbited the comet for over 10 months of up close observation, coming at times to as close as 8 kilometers. It is equipped with a suite 11 instruments to analyze every facet of the comet’s nature and environment.

ESA Philae lander approaches comet 67P/Churyumov–Gerasimenko on 12 November 2014 as imaged from Rosetta orbiter after deployment and during seven hour long approach for 1st ever  touchdown on a comets surface.  Credit:  ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA - Composition by Marco Di Lorenzo/Ken Kremer
ESA Philae lander approaches comet 67P/Churyumov–Gerasimenko on 12 November 2014 as imaged from Rosetta orbiter after deployment and during seven hour long approach for 1st ever touchdown on a comets surface. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA – Composition by Marco Di Lorenzo/Ken Kremer

Currently, Comet 67P is still becoming more and more active as it orbits closer and closer to the sun over the next two months. The mission extension will enable researchers to a far greater period of time to compare the comets activity, physical and chemical properties and evolution ‘before and after’ they arrive at perihelion some six weeks from today.

The pair reach perihelion on August 13, 2015 at a distance of 186 million km from the Sun, between the orbits of Earth and Mars.

“We’ll be able to monitor the decline in the comet’s activity as we move away from the Sun again, and we’ll have the opportunity to fly closer to the comet to continue collecting more unique data. By comparing detailed ‘before and after’ data, we’ll have a much better understanding of how comets evolve during their lifetimes.”

Because the comet is nearly at its peak of outgassing and dust spewing activity, Rosetta must observe the comet from a stand off distance, while still remaining at a close proximity, to avoid damage to the probe and its instruments.

Furthermore, the Philae lander “awoke” earlier this month after entering a sven month hibernation period after successfully compleing some 60 hours of science observations from the surface.

Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com
Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com

As the comet again edges away from the sun and becomes less active, the team will attempt to land Rosetta on comet 67P before it runs out of fuel and the energy produced from the huge solar panels is insufficient to continue mission operations.

“This time, as we’re riding along next to the comet, the most logical way to end the mission is to set Rosetta down on the surface,” says Patrick Martin, Rosetta Mission Manager.

“But there is still a lot to do to confirm that this end-of-mission scenario is possible. We’ll first have to see what the status of the spacecraft is after perihelion and how well it is performing close to the comet, and later we will have to try and determine where on the surface we can have a touchdown.”

During the extended mission, the team will use the experience gained in operating Rosetta in the challenging cometary environment to carry out some new and potentially slightly riskier investigations, including flights across the night-side of the comet to observe the plasma, dust, and gas interactions in this region, and to collect dust samples ejected close to the nucleus, says ESA.

Rosetta’s lander Philae has returned the first panoramic image from the surface of a comet. The view as it has been captured by the CIVA-P imaging system, shows a 360º view around the point of final touchdown. The three feet of Philae’s landing gear can be seen in some of the frames.  Superimposed on top of the image is a sketch of the Philae lander in the configuration the lander team currently believe it is in.  The view has been processed to show further details.   Credit: ESA/Rosetta/Philae/CIVA. Post processing: Ken Kremer/Marco Di Lorenzo
Rosetta’s lander Philae has returned the first panoramic image from the surface of a comet. The view as it has been captured by the CIVA-P imaging system, shows a 360º view around the point of final touchdown. The three feet of Philae’s landing gear can be seen in some of the frames. Superimposed on top of the image is a sketch of the Philae lander in the configuration the lander team currently believe it is in. The view has been processed to show further details. Credit: ESA/Rosetta/Philae/CIVA. Post processing: Ken Kremer/Marco Di Lorenzo

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about Rosetta, SpaceX, Europa, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

Jun 25-28: “SpaceX launch, Orion, Commercial crew, Curiosity explores Mars, Antares and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

This single frame Rosetta navigation camera image was taken from a distance of 77.8 km from the centre of Comet 67P/Churyumov-Gerasimenko on 22 March 2015. The image has a resolution of 6.6 m/pixel and measures 6 x 6 km. The image is cropped and processed to bring out the details of the comet’s activity. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
This single frame Rosetta navigation camera image was taken from a distance of 77.8 km from the centre of Comet 67P/Churyumov-Gerasimenko on 22 March 2015. The image has a resolution of 6.6 m/pixel and measures 6 x 6 km. The image is cropped and processed to bring out the details of the comet’s activity. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Rosetta Discovery of Surprise Molecular Breakup Mechanism in Comet Coma Alters Perceptions

A NASA science instrument flying aboard the European Space Agency’s (ESA) Rosetta spacecraft has made a very surprising discovery – namely that the molecular breakup mechanism of “water and carbon dioxide molecules spewing from the comet’s surface” into the atmosphere of comet 67P/Churyumov-Gerasimenko is caused by “electrons close to the surface.”

The surprising results relating to the emission of the comet coma came from measurements gathered by the probes NASA funded Alice instrument and is causing scientists to completely rethink what we know about the wandering bodies, according to the instruments science team.

“The discovery we’re reporting is quite unexpected,” said Alan Stern, principal investigator for the Alice instrument at the Southwest Research Institute (SwRI) in Boulder, Colorado, in a statement.

“It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets.”

A paper reporting the Alice findings has been accepted for publication by the journal Astronomy and Astrophysics, according to statements from NASA and ESA.

Alice is a spectrograph that focuses on sensing the far-ultraviolet wavelength band and is the first instrument of its kind to operate at a comet.

Until now it had been thought that photons from the sun were responsible for causing the molecular breakup, said the team.

The carbon dioxide and water are being released from the nucleus and the excitation breakup occurs barely half a mile above the comet’s nucleus.

“Analysis of the relative intensities of observed atomic emissions allowed the Alice science team to determine the instrument was directly observing the “parent” molecules of water and carbon dioxide that were being broken up by electrons in the immediate vicinity, about six-tenths of a mile (one kilometer) from the comet’s nucleus.”

The excitation mechanism is detailed in the graphic below.

Rosetta’s continued close study of Comet 67P/Churyumov-Gerasimenko has revealed an unexpected process at work close to the comet nucleus that causes the rapid breakup of water and carbon dioxide molecules.   Credits: ESA/ATG medialab; ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; ESA/Rosetta/NavCam – CC BY-SA IGO 3.0
Rosetta’s continued close study of Comet 67P/Churyumov-Gerasimenko has revealed an unexpected process at work close to the comet nucleus that causes the rapid breakup of water and carbon dioxide molecules. Credits: ESA/ATG medialab; ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA; ESA/Rosetta/NavCam – CC BY-SA IGO 3.0

“The spatial variation of the emissions along the slit indicates that the excitation occurs within a few hundred meters of the surface and the gas and dust production are correlated,” according to the Astronomy and Astrophysics journal paper.

The data shows that the water and CO2 molecules break up via a two-step process.

“First, an ultraviolet photon from the Sun hits a water molecule in the comet’s coma and ionises it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energising them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice.”

“Similarly, it is the impact of an electron with a carbon dioxide molecule that results in its break-up into atoms and the observed carbon emissions.”

After a decade long chase of over 6.4 billion kilometers (4 Billion miles), ESA’s Rosetta spacecraft arrived at the pockmarked Comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014 for history’s first ever attempt to orbit a comet for long term study.

Since then, Rosetta deployed the Philae landing craft to accomplish history’s first ever touchdown on a comets nucleus. It has also orbited the comet for over 10 months of up close observation, coming at times to as close as 8 kilometers. It is equipped with a suite 11 instruments to analyze every facet of the comet’s nature and environment.

Comet 67P is still becoming more and more active as it orbits closer and closer to the sun over the next two months. The pair reach perihelion on August 13, 2015 at a distance of 186 million km from the Sun, between the orbits of Earth and Mars.

Alice works by examining light emitted from the comet to understand the chemistry of the comet’s atmosphere, or coma and determine the chemical composition with the far-ultraviolet spectrograph.

According to the measurements from Alice, the water and carbon dioxide in the comet’s atmospheric coma originate from plumes erupting from its surface.

“It is similar to those that the Hubble Space Telescope discovered on Jupiter’s moon Europa, with the exception that the electrons at the comet are produced by solar radiation, while the electrons at Europa come from Jupiter’s magnetosphere,” said Paul Feldman, an Alice co-investigator from the Johns Hopkins University in Baltimore, Maryland, in a statement.

Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com
Rosetta discovered an unexpected process at comet nucleus that causes the rapid breakup of water and carbon dioxide molecules. Jets of gas and dust are blasting from the active neck of comet 67P/Churyumov-Gerasimenko in this photo mosaic assembled from four images taken on 26 September 2014 by the European Space Agency’s Rosetta spacecraft at a distance of 26.3 kilometers (16 miles) from the center of the comet. Credit: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer/kenkremer.com

Other instruments aboard Rosetta including MIRO, ROSINA and VIRTIS, which study relative abundances of coma constituents, corroborate the Alice findings.

“These early results from Alice demonstrate how important it is to study a comet at different wavelengths and with different techniques, in order to probe various aspects of the comet environment,” says ESA’s Rosetta project scientist Matt Taylor, in a statement.

“We’re actively watching how the comet evolves as it moves closer to the Sun along its orbit towards perihelion in August, seeing how the plumes become more active due to solar heating, and studying the effects of the comet’s interaction with the solar wind.”

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Weekly Space Hangout – May 29, 2015: Dr. Bradley M. Peterson

Host: Fraser Cain (@fcain)
Special Guest: This week we welcome Dr. Bradley M. Peterson, whose research is directed towards determination of the physical nature of active galactic nuclei.
Guests:
Jolene Creighton (@jolene723 / fromquarkstoquasars.com)
Charles Black (@charlesblack / sen.com/charles-black)
Brian Koberlein (@briankoberlein / briankoberlein.com)
Dave Dickinson (@astroguyz / www.astroguyz.com)
Morgan Rehnberg (cosmicchatter.org / @MorganRehnberg )
Alessondra Springmann (@sondy)
Continue reading “Weekly Space Hangout – May 29, 2015: Dr. Bradley M. Peterson”

Weekly Space Hangout – April 17, 2015: Amy Shira Teitel and “Breaking the Chains of Gravity”

Host: Fraser Cain (@fcain)
Special Guest: Amy Shira Teitel (@astVintageSpace) discussing space history and her new book Breaking the Chains of Gravity
Guests:
Morgan Rehnberg (cosmicchatter.org / @MorganRehnberg )

This Week’s Stories:
Falcon 9 launch and (almost!) landing
NASA Invites ESA to Build Europa Piggyback Probe
Bouncing Philae Reveals Comet is Not Magnetised
Astronomers Watch Starbirth in Real Time
SpaceX Conducts Tanking Test on In-Flight Abort Falcon 9
Rosetta Team Completely Rethinking Comet Close Encounter Strategy
Apollo 13 Custom LEGO Minifigures Mark Mission’s 45th Anniversary
LEGO Launching Awesome Spaceport Shuttle Sets in August
New Horizons Closes in on Pluto
Work Platform to be Installed in the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida.
Watching the Sunsets of Mars Through Robot Eyes: Photos
NASA Invites ESA to Build Europa Piggyback Probe
ULA Plans to Introduce New Rocket One Piece at a Time
Two Mysterious Bright Spots on Dwarf Planet Ceres Are Not Alike
18 Image Montage Show Off Comet 67/P Activity
ULA’s Next Rocket To Be Named Vulcan
NASA Posts Huge Library of Space Sounds And You’re Free to Use Them
Explaining the Great 2011 Saturn Storm
Liquid Salt Water May Exist on Mars
Color Map Suggests a Once-Active Ceres
Diverse Destinations Considered for New Interplanetary Probe
Paul Allen Asserts Rights to “Vulcan” Trademark, Challenging Name of New Rocket
First New Horizons Color Picture of Pluto and Charon
NASA’s Spitzer Spots Planet Deep Within Our Galaxy
Icy Tendrils Reaching into Saturn Ring Traced to Their Source
First Signs of Self-Interacting Dark Matter?
Anomaly Delays Launch of THOR 7 and SICRAL 2
Nearby Exoplanet’s Hellish Atmosphere Measured
The Universe Isn’t Accelerating As Fast As We Thought
Glitter Cloud May Serve As Space Mirror
Cassini Spots the Sombrero Galaxy from Saturn
EM-1 Orion Crew Module Set for First Weld Milestone in May
Special Delivery: NASA Marshall Receives 3D-Printed Tools from Space
The Roomba for Lawns is Really Pissing Off Astronomers
Giant Galaxies Die from the Inside Out
ALMA Reveals Intense Magnetic Field Close to Supermassive Black Hole
Dawn Glimpses Ceres’ North Pole
Lapcat A2 Concept Sup-Orbital Spaceplane SABRE Engine Passed Feasibility Test by USAF Research Lab
50 Years Since the First Full Saturn V Test Fire
ULA CEO Outlines BE-4 Engine Reuse Economic Case
Certification Process Begins for Vulcan to Carry Military Payloads
Major Advance in Artificial Photosynthesis Poses Win/Win for the Environment
45th Anniversary [TODAY] of Apollo 13’s Safe Return to Earth
Hubble’s Having A Party in Washington Next Week (25th Anniversary of Hubble)

Don’t forget, the Cosmoquest Hangoutathon is coming soon!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Google+, Universe Today, or the Universe Today YouTube page.

You can join in the discussion between episodes over at our Weekly Space Hangout Crew group in G+, and suggest your ideas for stories we can discuss each week!

Weekly Space Hangout – Nov. 14, 2014: Holy Rosetta! We Landed on a Comet!

Host: Fraser Cain (@fcain)

Guests:
Morgan Rehnberg (cosmicchatter.org / @cosmic_chatter)
Brian Koberlein (@briankoberlein)
Alessondra Springmann (@sondy)
Ramin Skibba (@raminskibba)

Continue reading “Weekly Space Hangout – Nov. 14, 2014: Holy Rosetta! We Landed on a Comet!”

Glorious Global 3-D Mars from ISRO’s MOM and ESA’s Rosetta

Here’s another breathtakingly glorious view from India’s Mars Orbiter Mission (MOM) – her first global 3-D portrait of her new home careening around the Red Planet.

MOM is India’s first deep space voyager to explore beyond the confines of her home planet’s influence and just successfully arrived at the Red Planet after the “history creating” orbital insertion maneuver on Sept. 23/24 following a ten month journey.

This newly released 3-D view from MOM expands upon the initial 2-D global color view of Mars released by the Indian Space Research Organization (ISRO), India’s space agency. See below and detailed in my earlier story – here.

The 3-D image was generated from multiple pictures acquired by MOM’s on-board Mars Color Camera on Sept 28, 2014, from the very high altitude of approximately 74,500 kilometers as the spacecraft orbits Mars.

ISRO's Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74500 km on Sept. 28, 2014.  Credit: ISRO
ISRO’s Mars Orbiter Mission captures spectacular portrait of the Red Planet and swirling dust storms with the on-board Mars Color Camera from an altitude of 74,500 km on Sept. 28, 2014. Credit: ISRO

The images were taken by the tri-color camera as MOM swooped around the Red Planet in a highly elliptical orbit whose nearest point to Mars (periapsis) is at 421.7 km and farthest point (apoapsis) at 76,993.6 km, according to ISRO.

Therefore, the 3-D Red Planet portrait was captured nearly at apoapsis. And being three dimensional, it gives a stereo sense of the huge dust storm swirling over a large swath of the planet’s Northern Hemisphere set against the blackness of space.

Below right is the southern polar ice cap. To see the 3-D effect, whip out your handy pair of left-eye red, right-eye blue color anaglyph glasses.

And while we’re on the subject of spacely 3-D, it’s worth noting that another of humanity’s ground breaking probes currently making news – ESA’s comet hunting Rosetta probe – likewise snapped a glorious 3-D view of Mars way back in 2007, during the brief, but critical, gravity assist slingshot maneuver that flung Rosetta along her vast 10 year path through interplanetary space.

So by way of comparison let’s take a trip down memory lane and be sure to look back at Rosetta’s global 3-D Martian views (below) taken by the high resolution OSIRIS camera on 24 February 2007 at 19:28 CET from a distance of about 240,000 kilometers.

Mars 3-D anaglyph (black & white) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240 000 km.  Image resolution is about 5 km.  Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA
Mars 3-D anaglyph (black & white) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240,000 km. Image resolution is about 5 km. Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA

The Rosetta team created both color and black & white 3-D views of Mars.

Mars 3-D anaglyph (color) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240 000 km.  Image resolution is about 5 km.  Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA
Mars 3-D anaglyph (color) taken by ESA’s Rosetta spacecraft during Mars flyby on 24 February 2007 from a distance of about 240,000 km. Image resolution is about 5 km. Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA

And be sure to check out Rosetta’s 2-D true color view showing a different swatch of the Red Planet compared to MOM, along with a more expansive view of the southern polar ice cap.

The first true-colour image of Mars from ESA’s Rosetta generated using the OSIRIS orange (red), green and blue colour filters. The image was acquired on 24 February 2007 at 19:28 CET from a distance of about 240 000 km; image resolution is about 5 km/pixel. Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA
The first true-color image of Mars from ESA’s Rosetta generated using the OSIRIS orange (red), green and blue color filters. The image was acquired on 24 February 2007 at 19:28 CET from a distance of about 240,000 km; image resolution is about 5 km/pixel. Credit: MPS for OSIRIS Team MPS/UPD/LAM/ IAA/ RSSD/ INTA/ UPM/ DASP/ IDA

The $73 million MOM mission is expected to last at least six months.

MOM’s success follows closely on the heels of NASA’s MAVEN orbiter which also successfully achieved orbit barely two days earlier on Sept. 21 and could last 10 years or more.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer