“Planet” or “dwarf planet” … What is its nature? Those are among the questions.
The sharpest views yet of mysterious “young planet” Ceres taken by NASA’s fast approaching Dawn spacecraft have just been released and are tantalizing us with an “exciting and productive adventure in orbit” soon to come, Dr. Marc Rayman and Prof. Chris Russell, Dawn’s Mission Director and Principal Investigator, respectively, told AmericaSpace exclusively in detailed science mission commentary today about this “survivor of the ages.”
See the latest photos and animation from NASA’s Dawn above and below.
Ceres is a pristine icy world stemming from the formation of our Solar System and has never before been visited by any human-made spacecraft from Earth. It is the biggest body in the Asteroid Belt.
With each passing day the “fuzzy blob” that will teach us about our own origins, too, comes into sharper focus.
“Ceres is a survivor from the earliest days of the Solar System and is an example of the first bodies that formed in the solar system and that eventually came together to build the Earth and other planets,” Prof. Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles, told AmericaSpace.
“Ceres is just a ‘young planet’ even though it was formed 4.6 billion years ago!”
The spacecraft is in excellent shape and primed for its orbital arrival set for March 6, despite the earlier loss of reaction wheels, thanks to the team’s never-ending hard work.
The solar-powered Dawn will conduct an up-close investigation during its planned 16-month-long orbital survey.
“The spacecraft and instruments are fully healthy,” Dr. Marc Rayman, Dawn’s mission director and chief engineer of the Jet Propulsion Laboratory (JPL), Pasadena, Calif., told AmericaSpace.
“Thanks to our recovery work, we don’t need the failed reaction wheels, so we are in good shape for an exciting and productive adventure in orbit around this dwarf planet!”
Until today, the best views of Ceres were taken by NASA’s Hubble Space Telescope back in 2003 and 2004.
But Dawn, launched back in 2007, is now closing in fast. And as of today the ion propulsion-powered vehicle is only about half the distance from the Earth to the Moon away.
The newest images from Dawn, taken 147,000 miles (237,000 kilometers) distant from Ceres on January 25, 2015, are at last exceeding those from Hubble. They are 43 pixels wide and more than 30 percent higher in resolution than Hubble’s, taken a decade ago from Earth orbit at a distance of over 150 million miles (about 241 million kilometers).
What have we learned about Ceres so far at this early stage? Any surprises?
“We have only just reached the resolution obtainable from Hubble so we have learned little than what we knew before,” Russell told AmericaSpace.
“We have been able to find the spot on the surface that Hubble found, so there have not been any great changes!”
“Surprise will come as we make significant advances over the Hubble image resolution.”
The Jan. 13 images clearly revealed the mysterious white spot, also detected in the prior Hubble images and also visible in the new Jan. 25 imagery from the framing cameras supplied by the Max Planck Institute for Solar System Research in Gottingen, Germany, and the German Aerospace Center (DLR) Institute of Planetary Research in Berlin.
This writer asked Marc Rayman and Chris Russell for their thoughts: What is the white spot? What is its nature?
“We don’t know what it is yet,” replied Rayman.
“What you see is a spot whose albedo is greater than the surrounding material so the eye makes it look white,” replied Russell. “When we see that on Earth we think that the material is newer and fresher.”
“So maybe that is a region of more recent activity. We will be looking at this closely!”
Could the white spot be an ice volcano?
“Anything that large probably is not an ice volcano, because it would produce too much water to be consistent with the Herschel observations,” Rayman elaborated.
Ceres is the largest and most massive object in the main Asteroid Belt, which lies between Mars and Jupiter. It measures about the size of Texas with a diameter of approximately 590 miles (950 kilometers). But our knowledge of the diminutive world is next to nothing.
Scientists are keenly interested in Ceres as it may harbor an ocean of liquid water as large in volume as the oceans of Earth below a thick icy mantle despite its small size—and thus could be a potential abode for life.
But no one knows for sure, and unlocking the secrets to the most fundamental science questions of life and the Solar System’s formation is what Dawn’s objectives are all about.
What do the scientists see in the newest images? It almost looks like there may possibly be some deep gashes, grooves, or canyons—reminiscent of Vesta, visited earlier by Dawn for 14 months in 2011 and 2012.
“Right now we are too far to be able to distinguish albedo from topography,” replied Russell.
“The team is certainly asking the very same questions!”
Ceres doesn’t appear perfectly round in the images. Why is that? Is that an illusion?
“From HST measurements, Ceres has principal radii of (approximately) 487 x 487 x 454 km,” Rayman explained.
“So the equatorial diameter is only 7 percent more than the polar diameter. Some of what you are seeing may be because we do not see a fully illuminated disk. Also, the pixelation may cause it to look even more irregular.”
“Ceres rotates much faster than Earth albeit slower than Vesta,” Russell added.
“The centrifugal forces pulls it out of round some. We certainly will be studying its shape carefully as we expect it to be near hydrodynamic equilibrium.”
Dawn is an international science mission with collaboration between the U.S., Germany, and Italy. It is a project from NASA’s Discovery program and managed by JPL.
The ion-powered probe is equipped with three science instruments provided by the three nations to photograph and investigate the surface mineralogy and elemental composition of the gigantic asteroid.
Besides the cameras, the other two instruments—VIR and GRaND—were provided by the Italian Space Agency and the Italian National Institute for Astrophysics and Los Alamos National Laboratory in New Mexico and the Planetary Science Institute of Tucson, Ariz.
Dawn was launched Sept. 27, 2007, by a United Launch Alliance (ULA) Delta II Heavy rocket from Space Launch Complex-17B (SLC-17B) at Cape Canaveral Air Force Station, Fla.
It will soon make history as the first spacecraft to orbit two celestial bodies beyond Earth.
Asked to elaborate on the meaning of why have we dispatched the Dawn interplanetary spacecraft to Ceres, Russell had this to say:
“Many scientists have been looking forward to the moment when we could visit this ‘survivor of the ages’ and interview her,” Russell said.
“That is what we are doing now. It really is exciting!”
Stay tuned here for continuing updates!
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