from Space.com

This web page is a collection of information regarding the Dwarf Planet Ceres. It compiles documents and images from a variety of sources to try and create the most informative website about Ceres on the net. We hope that through this information you will be as informed about Ceres as any professional.

Why should you care about Ceres?

As far as we know, life needs water to survive — and lots of it to thrive. Ceres is the closest large celestial body to Earth which is thought to have an abundance of fresh water. It is also closest to the sun of any large icy body, which along with possible interior heat might warm it enough for subsurface liquid water to exist.

Important criteria for a human outpost in space are available resources. Dozens of probes have been tasked with finding water deposits on the Moon and Mars. Ceres may in fact have more water than we would ever need.

Thus, Ceres would not only be a great place to search for life, but a possible future destination for manned missions and outposts as well.

Ceres is also interesting historically. First it was a Planet, then it was an Asteroid, and now it is a Dwarf Planet. The one mission to Ceres, NASA’s Dawn Mission, was cancelled, reinstated, told to "Stand Down", "Indefinitely Postponed", publicly cancelled, placed under review, and finally reinstated and given a go for launch in June 2007. While Ceres may be one of the gems of our solar system, its nomenclature and single planned mission have had a turbulent past.

Documents and Files

Ceres Hubble Rotation Model (QuickTime Movie)
Dawn Mission Faq (PowerPoint)
Diversity of C-Class Asteroids (PDF)
Keck II AO Ceres (PowerPoint)
Light Curve Models of 20 Asteroids (PDF)
Light Curve Models of 30 Asteroids (PDF)
Reconstructing HST Images of Asteroids (JPEG)
Typical Old Astronomy Book Page (JPEG)
VLT AO Ceres (PDF)

Images

The first image of Ceres clearly showing its nearly round shape were Ultraviolet Hubble Space Telescope images with 50 km resolution taken in 1995. These showed an enigmatic dark spot which was nicknamed Piazzi after Ceres discoverer.

Better images were obtained in 2002 through use of the Keck II telescope using adaptive optics. Clearly notable are what appears to be a large crater with bright central peak, and a large dark spot. (See Keck II AO Ceres PowerPoint)

Hubble again imaged Ceres in 2003 and 2004. These images were used to create rotational videos and a rotational model. These images show a prominent white spot the nature of which is unknown. (Rotational videos in order: Mid-Ultraviolet, Visible Light, Near-Ultraviolet. See Ceres Hubble Rotation Model movie for model based on this data)

In 2004, Hubble was also able to acquire a color image of Ceres. This shows the prominent crater with central peak in the Northern hemisphere of Ceres seen in the Keck II images as well as the 2004 Hubble rotational videos. (See Color View of Ceres)

In 2004 the Very Large Telescope (VLT) using adaptive optics imaged Ceres. These images show a dark spot in the approximate location the Piazzi feature would be, as well as large brightness asymmetry. (See VLT AO Ceres PDF)

Reconstructed HST Wide-Field/Planetary Camera-2 images of Ceres show a possible water of hydration feature. (See Reconstructing HST Images of Asteroids JPEG)

Artists Conception of Ceres possible differentiated interior. (See article "Largest asteroid might contain more fresh water than Earth")

Size Comparisons

Here we have several size comparisons of Ceres vs. other objects of the solar system. Size charts such as these provoke questions: Could Ceres be geologically active? Miranda, a moon of Uranus is thought to have been active in the past, and Saturn's moon Enceladus is geologically active at present time. Both of these are icy bodies, as is Ceres, and both are smaller than Ceres.

Other Main Belt Dwarf Planets?

If other main belt asteroids could be proven to have attained a nearly round shape, then they too could be considered dwarf planets. This is unlikely however. 4 Vesta perhaps was round at some point in its past, but is now clearly un-spherical with an enormous crater dominating a vast area of its surface. While reconstructed Hubble images of asteroid 10 Hygiea seemed to point to it being spherical, newer light curve models point to a typical "potato asteroid". Light curve shape models of 2 Pallas and 511 Davida indicate distinctly un-spherical bodies, with 2 Pallas being egg-shaped and 511 Davida being potato shaped. Thus based on current available information, all asteroids (other than Ceres) large enough to theoretically pull themselves into a nearly round shape have not, and therefore do not meet the criteria for being classified as a "Dwarf Planet". Many have complained that the requirement of a body being "nearly round" is ambiguous, but clearly objects as irregularly shaped as Vesta, Pallas, Hygiea, and Davida appear to be, could never qualify as "nearly round".

Hubble Space Telescope models of 4 Vesta

Light Curve Models of 2 Pallas (See Light Curve Models Of 30 Asteroids PDF)

Reconstructed HST Image of 10 Hygiea (See Reconstructing HST Images of Asteroids JPEG)

Light Curve Models of 10 Hygiea (See Light Curve Models Of 20 Asteroids PDF)

Light Curve Models of 511 Davida (See Light Curve Models Of 30 Asteroids PDF)

Links

Bad Astronomy and Universe Today Forum (best astronomy forum out there)
The Encyclopedia of Astrobiology, Astronomy, and Spaceflight's entry on Ceres
HubbleSite: Color View of Ceres
Largest asteroid might contain more fresh water than Earth
NASA's Dawn mission to Vesta and Ceres
Selected Asteroids (lots of good information)
The Planetary Society: Asteroid 1 Ceres (an up-to-date summary of knowledge about Ceres)
Solar system's damp start written in asteroid's rock
Squashed asteroid has planet-like qualities
The Symbols and Names of the Asteroids
When Did the Asteroids Become Minor Planets?
Wikipedia Encyclopedia page for Ceres (very helpful)
Wikipedia list of noteworthy asteroids
Wikipedia entry for the Dawn Mission

Contact

Do you have additional information on Ceres? We'd be happy to put it up on this web page. Or maybe you'd just like to give us your comments! Email us.