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Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘space travel

[BLOG] Some Wednesday links

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  • blogTO and Torontoist both report on the remarkable Honest Ed’s plan. (More than a thousand residential units, all rental? That’s rare.)
  • The Dragon’s Gaze notes the confirmation of a hard-to-find hot Jupiter orbiting BD-20 1790.
  • The Dragon’s Tales reports on the mysterious explosion of an American military satellite.
  • The Everyday Sociology Blog observes that raw talent is not nearly enough to ensure, that capital of all kinds is needed.
  • Joe. My. God. celebrates Slovenia’s legalization of same-sex marriage and notes Russia’s effort to block benefits for the same-sex partners of United Nations employees.
  • Language Hat is apparently not fond of National Grammar Day.
  • Language Log is critical of the BBC claim that a southern African group cannot see blue.
  • Lawyers, Guns and Money starts a discussion about India’s new aircraft carrier.
  • Marginal Revolution suggests that the Greeks are badly overstretched as individuals.
  • The Planetary Society Blog’s Emily Lakdawalla considers Ceres.
  • Towleroad notes the Russian government’s revenge on an lesbian couple who embarrassed an anti-gay politician.
  • Transit Toronto notes that the TTC now has a fourth super-long streetcar.
  • The Understanding Society Blog looks at how knowledge is reproduced globally.
  • Window on Eurasia criticizes the geopolitics of Eurasianism and warns of Russian involvement in Latvia.
  • The Financial Times‘ World blog notes the many issues with the Greek job market.

[LINK] “Bright Spots on Ceres Likely Ice, Not Cryovolcanoes”

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Universe Today’s Nancy Atkinson reports that speculation the bright spots on Ceres are ice volcanoes, erupting water from its interior, is likely false.

“These spots are extremely surprising and have been puzzling to the team and everyone that has seen them,” said Deputy Principal Investigator Carol Raymond. “The team is really, really excited about this feature because it is unique in the solar system.”

[. . .]

First, Raymond said the spots are consistent with highly reflective materials that may contain ice or salts. As an example of this, this morning, Cassini imaging lead Carolyn Porco tweeted an image of exposures of bright ice on Saturn’s moon Phoebe.

[. . .]

Secondly, Raymond said if the bright spots were a cryovolcano, they would expect to see some type of surface evidence of a mound, peak or crack. “We don’t see that with the bright spots so a cryovolcano is unlikely,” she said.

[. . .]

Third, — and this is also for anyone who may be thinking there is a beam or light-creating mechanism on the surface — team member Chris Russell said there is quite conclusive evidence that the spots are reflecting light, not creating light.

“We have followed the light curve into the terminator,” he said. “The spots do get darker and then go out when the terminator is reached.”

Written by Randy McDonald

March 4, 2015 at 11:21 pm

[LINK] “Seeing Ceres: Then and Now”

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As Dawn approaches Ceres, Centauri Dreams’ Paul Gilster shares some classic imaginings of Ceres and various other asteroids. They may have gotten some gross details right, actually.

I’m interested in how we depict astronomical objects, a fascination dating back to a set of Mount Palomar photographs I bought at Adler Planetarium in Chicago when I was a boy. The prints were large and handsome, several of them finding a place on the walls of my room. I recall an image of Saturn that seemed glorious in those days before we actually had an orbiter around the place. The contrast between what we could see then and what we would soon see up close was exciting. I was convinced we were about to go to these worlds and learn their secrets. Then came Pioneer, and Voyager, and Cassini.

And, of course, Dawn. As we discover more and more about Ceres, the process repeats itself, as it will again when New Horizons reaches Pluto/Charon. Below is a page from a book called Picture Atlas of Our Universe, published in 1980 by the National Geographic. Larry Klaes forwarded several early images last week as a reminder of previous depictions of the main belt’s largest asteroid, or dwarf planet, or whatever we want to call it. Here the artwork isn’t all that far off the mark for Ceres, though Vesta would turn out to be a good deal less spherical than predicted. No mention of a possible Ceres ocean in the depictions of this time; all that would come later.

The recent Dawn imagery has us buzzing about the two bright spots on Ceres that, of course, were unknown to our artist in 1980. From 46,000 kilometers, all we can do is admit how little we know[.]

Written by Randy McDonald

March 4, 2015 at 11:18 pm

[BLOG] Some Tuesday links

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  • The Big Picture looks at the uses of oil barrels around the world.
  • blogTO wonders if the Annex is ready for a condo boom.
  • Centauri Dreams features a guest post from Andrew Lepage noting how odd spectra on Mars were misidentified as proof of life.
  • Crooked Timber notes a student occupation of the University of Amsterdam’s headquarters.
  • Discover‘s The Crux makes a poor argument that space probe visits to Pluto and Ceres will lead to the redefinition of these worlds as planets.
  • The Dragon’s Gaze looks at an odd pulsating hot subdwarf B star with a brown dwarf.
  • The Dragon’s Tales suggests chemical mechanisms for life on Titan, and explains the differences in water plumes between Europa and Enceladus.
  • A Fistful of Euros notes political conflict in Germany.
  • Discover‘s Inkfist notes that birds from harsher climates are smarters.
  • Joe. My. God. shares Madonna’s critique of ageism.
  • Languages of the World examines the genesis of the English language.
  • Marginal Revolution notes Japanese funerals for robots, suggests Facebook usage makes people less happy, and notes family formation in Europe.
  • John Moyer examines punctuation.
  • Steve Munro maps out routes for a Scarborough subway.
  • The Planetary Society Blog looks at science on Pluto.
  • pollotenchegg maps the distribution of ethnically mixed households in Ukraine.
  • The Power and the Money’s Noel Maurer looks at how Panama successfully made use of price controls, and why.
  • Progressive Download’s John Farrell wonders what is the rush for three-parent IVF therapy.
  • Transit Toronto explains how old TTC tickets can be exchanged.
  • Window on Eurasia notes the importance of Belarus for the Baltic States, notes the newly-debatable borders of the former Soviet Union, suggests Tatarstan is unhappy with Russian federalism, and looks at the small grounds for Russian-Ukrainian hostilities.

[LINK] “Ceres’ Deepening Mysteries”

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At the Planetary Society Blog, Marc Rayman describes how, as the Dawn probe approaches Ceres, that dwarf planet is revealing more mysteries.

The Dawn spacecraft is performing flawlessly as it conducts the first exploration of the first dwarf planet. Each new picture of Ceres reveals exciting and surprising new details about a fascinating and enigmatic orb that has been glimpsed only as a smudge of light for more than two centuries. And yet as that fuzzy little blob comes into sharper focus, it seems to grow only more perplexing.

Dawn is showing us exotic scenery on a world that dates back to the dawn of the solar system, more than 4.5 billion years ago. Craters large and small remind us that Ceres lives in the rough and tumble environment of the main asteroid belt between Mars and Jupiter, and collectively they will help scientists develop a deeper understanding of the history and nature not only of Ceres itself but also of the solar system.

Even as we discover more about Ceres, some mysteries only deepen. It certainly does not require sophisticated scientific insight to be captivated by the bright spots. What are they? At this point, the clearest answer is that the answer is unknown. One of the great rewards of exploring the cosmos is uncovering new questions, and this one captures the imagination of everyone who gazes at the pictures sent back from deep space.

Other intriguing features newly visible on the unfamiliar landscape further assure us that there will be much more to see and to learn — and probably much more to puzzle over — when Dawn flies in closer and acquires new photographs and myriad other measurements. Over the course of this year, as the spacecraft spirals to lower and lower orbits, the view will continue to improve. In the lowest orbit, the pictures will display detail well over one hundred times finer than the RC2 pictures returned a few days ago (and shown below). Right now, however, Dawn is not getting closer to Ceres. On course and on schedule for entering orbit on March 6, Earth’s robotic ambassador is slowly separating from its destination.

“Slowly” is the key. Dawn is in the vicinity of Ceres and is not leaving. The adventurer has traveled more than 900 million miles (1.5 billion kilometers) since departing from Vesta in 2012, devoting most of the time to using its advanced ion propulsion system to reshape its orbit around the sun to match Ceres’ orbit. Now that their paths are so similar, the spacecraft is receding from the massive behemoth at the leisurely pace of about 35 mph (55 kilometers per hour), even as they race around the sun together at 38,700 mph (62,300 kilometers per hour). The probe is expertly flying an intricate course that would be the envy of any hotshot spaceship pilot. To reach its first observational orbit — a circular path from pole to pole and back at an altitude of 8,400 miles (13,500 kilometers) — Dawn is now taking advantage not only of ion propulsion but also the gravity of Ceres.

Written by Randy McDonald

February 28, 2015 at 12:08 am

[LINK] “Russia to keep its part of space station after its duty ends”

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The Dragon’s Tales linked to this Associated Press report suggesting Russia’s interest in undocking the modules it built for the ISS in 2024, with the aim of using them for its own station.

Russia’s space agency expects the International Space Station to stay in orbit through 2024, and plans to create its own space outpost with its segment of the station after that.

Roscosmos’ scientific council concluded Tuesday that several Russian modules could eventually be undocked to “perform the task of ensuring Russia’s guaranteed presence in space.”

The ISS, run by the United States, Russia, the European Space Agency and other international partners, is set to remain operational at least through 2024. Russia’s own Mir space station was deorbited in 2001 after 15 years as Moscow sought to concentrate its resources on the ISS.

Written by Randy McDonald

February 28, 2015 at 12:04 am

[LINK] “Strategic Defense: Military Uses of the Moon & Asteroids (1983)”

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At his fascinating Beyond Apollo blog at Wired, David S.F. Portree notes how in the 1980s, Cold War America began to consider the defense applications of the Moon and near-Earth asteroids.

In February 1977, James Arnold, a UCSD chemistry professor, had spoken with NASA Administrator Fletcher about making the exploitation of near-Earth space resources a major new focus for NASA. He subsequently summed up his thoughts in a detailed two-page letter to Fletcher. Three years later, Arnold became the first director of Calspace, which had its origins in California Governor Jerry Brown’s enthusiasm for technological development in his state.

Arnold’s deputy in 1983-1984, planetary scientist Stewart Nozette, organized the La Jolla workshop, which brought together 36 prominent scientists and engineers from aerospace companies, national laboratories, NASA centers, the Department of Defense, and defense think-tanks to weigh in on SDI’s potential use of moon and asteroid resources. Nozette also edited the workshop report, which Arnold submitted to Fletcher on 18 August 1983. A revised version of the workshop report was completed on 31 October 1983; this post is based upon the latter version.

In the late 1970s, NASA, aerospace companies, and universities expended a great deal of time and effort on planning large structures – for example, Solar Power Satellites – that would be assembled in space. Some of these plans relied on space resources. In the cover letter to the La Jolla workshop report, Nozette explained that these studies, though conducted “in an unfocused and low priority vein,” had laid the groundwork for SDI exploitation of moon and asteroid resources. The La Jolla workshop was, he added, the first to consider the defense implications of the 1970s concepts.

At the time of the La Jolla workshop, relatively little was known of near-Earth space resources. Five Lunar Orbiter spacecraft had imaged much of the moon at modest resolution and selected portions of it – most corresponding to potential Apollo landing sites – at higher resolution. NASA had landed Apollo astronauts at six sites between 1969 and 1972 and scientists had analyzed many of the more than 2400 geologic samples they collected. In addition, Apollo astronauts had surveyed the moon from lunar orbit using remote sensors. These provided low-resolution data on the composition of perhaps 10% of the lunar surface.

Scientists had hypothesized since 1961 that permanently shadowed craters at the lunar poles might contain ice deposited by comet impacts. The lunar poles, far from the “Apollo Zone” – the near-equatorial region where orbital mechanics dictated the Apollo Lunar Modules could land – nevertheless remained unexplored.

Written by Randy McDonald

February 26, 2015 at 11:28 pm

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