Starship Asterisk*

BDanielMayfield wrote:

THX1138 wrote:I'm not understanding why pictures were available all the way up until Dawn was close enough to see the rock up close, in orbit. Now that its close enough to see what the bright spots are................We have to wait????

Just listened to the press conference Rob linked to and the real reason they kept giving for the delay in new photos coming out is that Dawn is now orbiting on the "dark side" of Ceres. The higher the orbit and the lower the mass of the body being orbited, the slower the orbit. Dawn will be over the sunlit side of Ceres in April.

AmericaSpace wrote:And because of the angle of the approach trajectory, Ceres will not be very illuminated until the end of April when Dawn reaches its initial science altitude orbit of about 8,400 miles (13,500 kilometers).

Dawn’s next imaging session is scheduled for early March, but likely won’t reveal much more.

“The next images will be a little bit better. But the resolution doesn’t get much better until late April!” Russell explained.

[url=http://www.jpl.nasa.gov/spaceimages/details.php?id=pia19063][b][i]Dawn's First Color Map of Ceres[/i][/b][/url] [b][i]Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA[/i][/b]

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A new color map of dwarf planet Ceres, which NASA's Dawn spacecraft has been orbiting since March, reveals the diversity of the surface of this planetary body. Differences in morphology and color across the surface suggest Ceres was once an active body, Dawn researchers said today at the 2015 General Assembly of the European Geosciences Union in Vienna. ...

Ceres' surface is heavily cratered, as expected, but appears to have fewer large craters than scientists anticipated. It also has a pair of very bright neighboring spots in its northern hemisphere. More detail will emerge after the spacecraft begins its first intensive science phase on April 23, from a distance of 8,400 miles (13,500 kilometers) from the surface, said Martin Hoffmann, investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany.

The visible and infrared mapping spectrometer (VIR), an imaging spectrometer that examines Ceres in visible and infrared light, has been examining the relative temperatures of features on Ceres' surface. Preliminary examination suggests that different bright regions on Ceres' surface behave differently, said Federico Tosi, investigator from the VIR instrument team at the Institute for Space Astrophysics and Planetology, and the Italian National Institute for Astrophysics, Rome. ...

Dawn Maps Ceres in False Color (S&T, Camille M. Carlisle) wrote:The color scheme in this map is inverted from reality: the version JPL released assigns the short, bluer wavelengths to be red, and the long, infrared wavelengths (which the human eye can't see) to be blue. That seemed a wee daffy to me, so I asked what was up. Turns out the camera team wanted the map to look unreal: it's too early in the mission to unambiguously separate all the things that influence the surface's apparent color, and when the team made a map with a different color scheme, it led to misleading interpretations even among the team's own members. So instead they decided to emphasize the "false" in false-color and forestall confusion.

geckzilla wrote:Here is the image uninverted. Is it because blue makes people think of ice?

[img3="This animation shows the north pole of dwarf planet Ceres as seen
by Dawn on April 10, 2015. Dawn was at a distance of 21,000 miles
(33,000 kilometers) when its framing camera took these images.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA"]http://www.jpl.nasa.gov/images/dawn/201 ... 317-16.gif[/img3]

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After spending more than a month in orbit on the dark side of dwarf planet Ceres, NASA's Dawn spacecraft has captured several views of the sunlit north pole of this intriguing world. These images were taken on April 10 from a distance of 21,000 miles (33,000 kilometers), and they represent the highest-resolution views of Ceres to date.

Subsequent images of Ceres will show surface features at increasingly better resolution.

Dawn arrived at Ceres on March 6, marking the first time a spacecraft has orbited a dwarf planet. Previously, the spacecraft explored giant asteroid Vesta for 14 months from 2011 to 2012. Dawn has the distinction of being the only spacecraft to orbit two extraterrestrial targets.

Ceres, with an average diameter of about 590 miles (950 kilometers), is the largest body in the main asteroid belt between Mars and Jupiter. Dawn has been using its ion propulsion system to maneuver to its first science orbit at Ceres, which it will reach on April 23. The spacecraft will remain at a distance of 8,400 miles (13,500 kilometers) from the dwarf planet until May 9. Afterward, it will make its way to lower orbits.

http://photojournal.jpl.nasa.gov/catalog/PIA19320 wrote:

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This anaglyph of Ceres is part of a sequence of images taken by NASA's Dawn spacecraft April 24 to 26, 2015, from a distance of 8,500 miles (13,500 kilometers). This shows the same view as PIA19319.

[c]
Click on the image for the animation
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA[/c]

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The mysterious bright spots on the dwarf planet Ceres are better resolved in a new sequence of images taken by NASA's Dawn spacecraft on May 3 and 4, 2015. The images were taken from a distance of 8,400 miles (13,600 kilometers). ...

In this closest-yet view, the brightest spots within a crater in the northern hemisphere are revealed to be composed of many smaller spots. However, their exact nature remains unknown.

"Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice," said Christopher Russell, principal investigator for the Dawn mission from the University of California, Los Angeles.

These images offer scientists new insights into crater shapes and sizes, and a host of other intriguing geological features on the surface. The image resolution is 0.8 mile (1.3 kilometers) per pixel. ...

THX1138 wrote:YouTube / Ceres bright spots / Not very happy with the pictures (All Blurry) That NASA keeps releasing
That's all I'm going to say

geckzilla wrote:It's not magnification. Magnification is done by lenses.

Chris Peterson wrote:

geckzilla wrote:It's not magnification. Magnification is done by lenses.

The technical term for this sort of "over magnification" is "undersampling".

Ron-Astro Pharmacist wrote:

Chris Peterson wrote:

geckzilla wrote:It's not magnification. Magnification is done by lenses.

The technical term for this sort of "over magnification" is "undersampling".

Doesn't some magnification come from the primary objective mirror or lens? When I attach my camera to my 4 inch reflector the view is quite magnified without a lens.

Ron-Astro Pharmacist wrote:Wow. Now I know it's not my bailiwick but I think I understand a little of what you're saying. The focal length dictated by the tube length divided by the focal length of the eyepiece (or camera adaptor) is the magnification the eye can sense if it's in correct harmony with the eye lens vs retina focal length.