Rosetta’s Comet Already Sweating The Small Stuff, Far From The Sun

Artist's conception of Rosetta's target, 67P/Churyumov–Gerasimenko, which is losing two 5-ounce (150 millileter cups) of water every second while still 362 million miles (583 million kilometers) from the sun. The water vapor output will increase as the comet gets closer; these measurements were made on June 6, 2014. Credit: ESA

Feeling thirsty? If you could somehow capture the water vapor from Rosetta’s comet, you would have the equivalent of two water glasses every second. That’s more than scientists expected given that Comet 67P/Churyumov–Gerasimenko is still screaming into the inner solar system at more than double the distance from Mars to the Sun.

“We always knew we would see water vapor outgassing from the comet, but we were surprised at how early we detected it,” stated Sam Gulkis, the instrument’s principal investigator at NASA’s Jet Propulsion Laboratory in California.

“At this rate, the comet would fill an Olympic-size swimming pool in about 100 days. But, as it gets closer to the Sun, the gas production rate will increase significantly. With Rosetta, we have an amazing vantage point to observe these changes up close and learn more about exactly why they happen.”

Comets are sometimes called “dirty snowballs” because they are collection of debris and ices. From their origin points in the outer solar system, occasionally one will be pushed towards the Sun.

Artist's impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.
Artist’s impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.

As it gets closer, the ices bleed off and the comet develops an envelope of gases that eventually, with the Sun’s help, will turn into a tail. Some of the major “volatiles” include water, carbon monoxide, methanol and ammonia.

The observations were made on June 6 by an instrument called the Microwave Instrument for Rosetta Orbiter (MIRO), taken when the spacecraft was about 218,000 miles (350,000 km) away from its target. MIRO is trying to figure out the relative ratios of the ingredients of the coma, and will keep following along with the comet as it makes its closest approach to the sun in August 2015.

Rosetta, meanwhile, will get up close to Comet 67P/Churyumov–Gerasimenko by August and if all goes well, subsequently deploy a lander called Philae to check out the surface of the comet.

Source: European Space Agency

Rosetta Detects Water on its Target Comet

Artist's impression (from 2002) of Rosetta orbiting Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab

It’s no surprise that there is a lot of water in comets. The “dirty snowballs” (or dusty ice-balls, more accurately) are literally filled with the stuff, so much in fact it’s thought that comets played a major role in delivering water to Earth. But every comet is unique, and the more we learn about them the more we can understand the current state of our Solar System and piece together the history of our planet.

ESA’s Rosetta spacecraft is now entering the home stretch for its rendezvous with comet 67P/Churyumov-Gerasimenko in August. While it has already visually imaged the comet on a couple of occasions since waking from its hibernation, its instruments have now successfully identified water on 67P for the first time, from a distance of 360,000 km — about the distance between Earth and the Moon.

The detection comes via Rosetta’s Microwave Instrument for Rosetta Orbiter, or MIRO, instrument. The results were distributed this past weekend to users of the IAU’s Central Bureau of Astronomical Telegrams:

S. Gulkis, Jet Propulsion Laboratory, California Institute of Technology, on behalf of the Microwave Instrument on Rosetta Orbiter (MIRO) science team, reports that the (1_10)-(1_01) water line at 556.9 GHz was first detected in Comet 67P/Churyumov-Gerasimenko with the MIRO instrument aboard the Rosetta spacecraft on June 6.55, 2014 UT. The line area is 0.39 +/-0.06 K km/s with the line amplitude of 0.48 +/-0.06 K and the line width of 0.76 +/-0.12 km/s. At the time of the observations, the spacecraft to comet distance was ~360,000 km and the heliocentric distance of the comet was 3.93 AU. An initial estimate of the water production rate based on the measurements is that it lies between 0.5 x 10^25 molecules/s and 4 x 10^25 molecules/s.

Although recent images of 67P/C-G seem to show that the comet’s brightness has decreased over the past couple of months, it is still on its way toward the Sun and with that will come more warming and undoubtedly much more activity. These recent measurements by MIRO show that the comet’s water production rate is “within the range of models being used” by scientists to anticipate its behavior.

Rosetta image of Comet 67P/C-G on June 4, 2014, from a distance of 430,000 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Rosetta image of Comet 67P/C-G on June 4, 2014, from a distance of 430,000 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Read more: What Will Rosetta’s Comet Look Like?

This August Rosetta will become the first spacecraft to establish orbit around a comet and, in November, deploy its Philae lander onto its surface. Together these robotic explorers will observe first-hand the changes in the comet as it makes its closest approach to the Sun in August 2015. It’s going to be a very exciting year ahead, so stay tuned for more!

Learn more about the Rosetta mission here.

Source: ESA’s Rosetta blog

 

What Will Rosetta’s Comet Look Like? How Artists Over The Years Pictured It

Artist's impression (from 2002) of the Philae lander on Comet 67P/Churyumov-Gerasimenko. Credit: ESA / AOES Medialab

Comets are notoriously hard to predict — just ask those people on Comet ISON watch late in 2013. So as Rosetta approaches its cometary target, no one really knows what the comet will look like from up close. Yes, there are pictures of other cometary nuclei (most famously, Halley’s Comet) but this one could look completely different.

Several artists have taken a stab at imagining what Rosetta will see when it gets close to the comet in August, and what Philae will touch on when it reaches the surface in November. You can see their work throughout this article.

Meanwhile, the European Space Agency just issued an update on what they can see of 67P/Churyumov–Gerasimenko from half a million km away — the comet is quieter, they said.

“Strikingly, there is no longer any sign of the extended dust cloud that was seen developing around nucleus at the end of April and into May,” ESA stated in a press release. “Indeed, monitoring of the comet has shown a significant drop in its brightness since then.”

Artist's impression (from 2002) of Rosetta orbiting Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab
Artist’s impression (from 2002) of Rosetta orbiting Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab

This variability is common in comets, but it’s the first time it’s been seen from so close, ESA said. Comets warm up as they approach the sun, releasing ice, gas and dust that form a swarm of material.

“As comets are non-spherical and lumpy, this process is often unpredictable, with activity waxing and waning as they warm. The observations made over the six weeks from the end of April to early June show just how quickly the conditions at a comet can change,” ESA added.

For more about Philae’s landing, check out this past article from Universe Today.

Rosetta flies above the Philae lander on Comet 67P/Churyumov-Gerasimenko in this artist's impression from 2002. Credit: Astrium - E. Viktor
Rosetta flies above the Philae lander on Comet 67P/Churyumov-Gerasimenko in this artist’s impression from 2002. Credit: Astrium – E. Viktor
Artist's impression (from 2002) of the Philae lander during descent on Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab
Artist’s impression (from 2002) of the Philae lander during descent on Comet 67P/Churyumov-Gerasimenko. Credit: ESA, image by AOES Medialab
Rosetta flies above Comet 67P/Churyumov–Gerasimenko in this 2013 artist's impression. Credit: ESA–C. Carreau/ATG medialab
Rosetta flies above Comet 67P/Churyumov–Gerasimenko in this 2013 artist’s impression. Credit: ESA–C. Carreau/ATG medialab
Artist's impression (from 2013) of the Philae lander on the surface of Comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab
Artist’s impression (from 2013) of the Philae lander on the surface of Comet 67P/Churyumov-Gerasimenko. Credit: ESA/ATG medialab

It’s Alive! Rosetta’s Comet Flares As It Approaches The Sun

A close-up of comet 67P/Churyumov–Gerasimenko taken from 1.24 million miles (2 million km) away. The image was obtained by the Rosetta spacecraft in April 2014 as it approached the comet for a close-up view. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Wow! This image shows the target comet for the Rosetta mission starting to develop a tail. This bodes well for the European Space Agency spacecraft, which is on its way to study Comet 67P/Churyumov–Gerasimenko later this year to learn more about the origins of the solar system.

“It’s beginning to look like a real comet,” stated Holger Sierks, principal investigator for OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System.)

“It’s hard to believe that only a few months from now, Rosetta will be deep inside this cloud of dust and en route to the origin of the comet’s activity,” added Sierks, who is with the Max Planck Institute for Solar System Research in Germany.

The picture was one of a series taken over six weeks, between March 27 and May 4, as the spacecraft zoomed to within 1.24 million miles (two million kilometers) of the target. You can see the full animation by clicking on the image below.

Comet 67P/Churyumov–Gerasimenko develops a coma in this sequence of pictures taken by Rosetta, a European Space Agency spacecraft. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Comet 67P/Churyumov–Gerasimenko develops a coma in this sequence of pictures taken by Rosetta (click the picture to see the animation), a European Space Agency spacecraft. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The comet is now about four times as far from the Sun as the Earth is. Even from afar, the Sun’s heat is warming the comet’s ice, causing dust and vapor to carry out into space — forming the coma. The coma will develop into a long tail when the comet gets even closer to the sun.

Rosetta will be the comet’s companion as it draws closer to the sun; its closest approach will be in August 2015, when it is between the orbits of Earth and Mars. So far, the spacecraft’s 11 instruments appear to be in excellent health, ESA stated, although the agency is remaining cautious as the rendezvous date approaches. The spacecraft will begin orbital insertion activities later this month, and send out its Philae lander in November.

“We have a challenging three months ahead of us as we navigate closer to the comet, but after a 10-year journey it’s great to be able to say that our spacecraft is ready to conduct unique science at comet 67P/C-G,” stated Fred Jansen, ESA’s Rosetta mission manager.

Source: European Space Agency

Rosetta’s Philae Lander Snaps a Selfie

Rosetta's solar panels as seen by Philae's CIVA imaging system on April 14, 2014. Credit: ESA/Rosetta/Philae/CIVA

Philae is awake… and taking pictures! This image, acquired last night with the lander’s CIVA (Comet nucleus Infrared and Visible Analyzer) instrument, shows the left and right solar panels of ESA’s well-traveled Rosetta spacecraft, upon which the 100-kilogram Philae is mounted.

Philae successfully emerged from hibernation on March 28 via a wake-up call from ESA.

After over a decade of traveling across the inner Solar System, Rosetta and Philae are now in the home stretch of their ultimate mission: to orbit and achieve a soft landing on comet 67/P Churyumov-Gerasimenko. It will be the first time either feat has ever been attempted by a spacecraft. Read more here.

Source: ESA Rosetta Blog

Fly to Rosetta’s Comet with this New Interactive Visualization

Frame from the Rosetta Mission simulation shows the probe and comet when closest to the sun in late 2015. Credit: INOVE

Hang onto your space helmets.  With a few moves of the mouse, you can now follow the European Rosetta mission to its target comet with this interactive 3-D simulator. Go ahead and give it a click – it’s live! The new simulator was created by INOVE Space Models, the same group that gave us the 3-D solar system and Comet ISON interactive models.

The embedded version gives you a taste, so be sure to also check out the full-screen version. You can either click play to watch the mission from start to finish or you can drop it at key points by selecting from list of 11 highlights on the left side of your screen. A tick-tock at the bottom of the screen helps reference the time and what the spacecraft is doing at that moment in the video.

To interact with the model, simply click the screen. The action stops, allowing you to zoom in and out by scrolling; to change orbital viewpoints hold down the mouse button and drag. So easy!

Simulator view of Rosetta's first Earth flyby / gravity assist in March 2005. The probe flew by Earth three times and Mars once to conserve fuel and send it beyond the asteroid belt to rendezvous with Comet Churyumov-Gerasimenko. Credit: INOVE
Simulator view of Rosetta’s first Earth flyby / gravity assist in March 2005. The probe flew by Earth three times and Mars once to conserve fuel and send it beyond the asteroid belt to rendezvous with Comet Churyumov-Gerasimenko. Credit: INOVE

I like the realism of the simulation, the attention paid to the planets’ variable spin rates and orbital periods and how well model illustrates the complicated maneuvers required to “fling” the probe to Comet Churyumov-Gerasimenko. And I do mean fling. Watching the video from a face-on solar system perspective I was struck  by how Rosetta’s flight path resembled a spiral after repeated gravity assists by Mars and Earth.

Rosetta heads toward Comet C-G after its final Earth flyby in this face-on view. Credit: INOVE
Rosetta heads toward Comet C-G after its final Earth flyby in this face-on view. Credit: INOVE

Whether you’re a teacher or an armchair space enthusiast looking for an easy-to-understand, graphic way to find out how Rosetta will meet its target, I doubt you’ll find a more effective tool.

ESA Awakens Rosetta’s Comet Lander

Artist's impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.

Little Philae is awake! ESA sent a wake-up call to the 100-kg (220-lb) lander riding aboard the Rosetta spacecraft this morning at 06:00 GMT, bringing it out of its nearly 33-month-long slumber and beginning its preparation for its upcoming (and historic) landing on the surface of a comet in November.

Unlike Rosetta, which awoke in January via a pre-programmed signal, Philae received a “personal wake-up call” from Earth, 655 million kilometers away.

Hello, world! ESA's Rosetta and Philae comet explorers are now both awake and well!
Hello, world! ESA’s Rosetta and Philae comet explorers are now both awake and well!

A confirmation signal from the lander was received by ESA five and a half hours later at 11:35 GMT.

After over a decade of traveling across the inner Solar System, Rosetta and Philae are now in the home stretch of their ultimate mission: to orbit and achieve a soft landing on the inbound comet 67/P Churyumov-Gerasimenko. It will be the first time either feat has ever been attempted — and hopefully achieved — by a spacecraft.

Read more: Rosetta Spacecraft Spies Its Comet As It Prepares For An August Encounter

After Rosetta maneuvers to meet up with the comet in May and actually enters orbit around it in August, it will search its surface for a good place for Philae to make its landing in November.

With a robotic investigator both on and around it, 67/P CG will reveal to us in intimate detail what a comet is made of and really happens to it as it makes its close approach to the Sun.

“Landing on the surface is the cherry on the icing on the cake for the Rosetta mission on top of all the great science that will be done by the orbiter in 2014 and 2015. A good chunk of this year will be spent identifying where we will land, but also taking vital measurements of the comet before it becomes highly active. No one has ever attempted this before and we are very excited about the challenge!”
– Matt Taylor, Rosetta project scientist

Meanwhile, today’s successful wake-up call let the Rosetta team know Philae is doing well. Further systems checks are planned for the lander throughout April.

Watch an animation of the deployment and landing of Philae on comet 67/P CG below:

Source: ESA’s Rosetta blog

Want to welcome Rosetta and Philae back on your computer? Download a series of ESA’s “Hello, World” desktop screens here.