Outer Solar System

Dawn: New Imagery of Ceres

January 20, 2015

Mark January 26 on your calendar. It’s the day when the Dawn spacecraft will take images of Ceres that should exceed the resolution of the Hubble Space Telescope. We’re moving into that new world discovery phase that is so reminiscent of the Voyager images, which kept re-writing our textbooks on the outer Solar System. 2015 […]

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Planets to Be Discovered in the Outer System?

January 16, 2015

Having just looked at the unusual ‘warped’ disk of HD 142527, I’m inclined to be skeptical when people make too many assumptions about where planets can form. Is our Solar System solely a matter of eight planets and a Kuiper Belt full of debris, with a vast cometary cloud encircling the whole? Or might there […]

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Naming Names in the Cosmos

January 15, 2015

How objects in the sky get named is always interesting to me. You may recall that the discovery of Uranus prompted some interesting naming activity. John Flamsteed, the English astronomer who was the first Astronomer Royal, observed the planet in 1690 and catalogued it as 34 Tauri, thinking it a star, as did French astronomer […]

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Dawn: Beginning Approach to Ceres

December 31, 2014

Speaking of spacecraft that do remarkable things, as we did yesterday in looking at the ingenious methods being used to lengthen the Messenger mission, I might also mention what is happening with Dawn. When the probe enters orbit around Ceres — now considered a ‘dwarf planet’ rather than an asteroid — in 2015, it will […]

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Are Europa’s Plumes Really There?

December 22, 2014

A new study of data from the Cassini Saturn orbiter has turned up useful information about, of all places, Europa. Cassini’s 2001 flyby of Jupiter en route to Saturn produced the Europa data that were recently analyzed by members of the probe’s ultraviolet imaging spectrograph (UVIS) team. We learn something striking: Most of the plasma […]

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Rosetta: New Findings on Cometary Water

December 11, 2014

Where did the water in Earth’s oceans come from? It’s an open question, but new data from the Rosetta mission, in particular its ROSINA instrument (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) indicate that terrestrial water probably did not come from comets like 67P/Churyumov-Gerasimenko, around which Rosetta has been orbiting since August. There is […]

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Deep Space: Moving Toward Encounter Mode

December 9, 2014

No spacecraft has ever traveled further to reach its primary target than New Horizons, now inbound to Pluto/Charon. From 4.6 billion kilometers from Earth (four hours, 26 minutes light travel time), the spacecraft has sent confirmation that its much anticipated wake-up call from ground controllers was a success. Since December 6, New Horizons has been […]

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Our Best View of Europa

November 25, 2014

Apropos of yesterday’s post questioning what missions would follow up the current wave of planetary exploration, the Jet Propulsion Laboratory has released a new view of NASA’s intriguing moon Europa. The image, shown below, looks familiar because it was published in 2001, though at lower-resolution and with considerable color enhancement. The new mosaic gives us […]

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New Horizons: Potential KBO Targets Identified

October 21, 2014

The welcome news that the Hubble Space Telescope has found three potential Kuiper Belt targets for New Horizons means that our hopes for an extended mission may be fulfilled. Pluto/Charon is an exciting target, but how much better to use the spacecraft to visit a Kuiper Belt object as well, a member of that vast […]

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Mimas: An Intriguing Interior

October 20, 2014

I like what Radwan Tajeddine (Cornell University) has to say about recent work on Saturn’s moon Mimas. The lead author of a paper on the subject in Science, Tajeddine compares recent Cassini observations of the moon to a child shaking a wrapped gift, trying to figure out what the package conceals. ‘Shaking’ Mimas in a […]

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