Images sent back from New Horizons gave scientists their first opportunity to see how big Kerberos is. It's much smaller than they expected, which raises new questions.Meanwhile, the Mars Reconnaissance Orbiter's instruments provided evidence that there's running water on Mars: every summer, on some crater slopes. It's not the Mars of Burroughs' Barsoom tales: but I think the planet is getting more interesting, the more we learn about it.
"Wonderful Things"
(From James Allen St. John, via Wikimedia Commons, used w/o permission.)
(A green Martian on his thoat: on Edgar Rice Burroughs' Barsoom.)
I enjoy fiction: speculative-, science-, and otherwise. But I also enjoy trying to keep up with what we're learning about this wonder-filled universe.Howard Carter, asked if he could see anything through "tiny breach in the top left hand corner" of a buried doorway, said: "Yes, wonderful things!"1
That's how I feel, when running into another piece from this cosmic puzzle collection we live in. As I've said before, this is a world of wonders. The trick is learning to notice them. (January 2, 2015; October 5, 2014)
This is where I explain why faith and reason, science and religion, get along — or should. Feel free to skip down to Pluto's Moon Kerberos: Answers Raise New Questions, or do whatever seems reasonable.
Science and technology are tools. Using them is part of being human. Studying the universe and using that knowledge is what we're supposed to do. (Catechism of the Catholic Church, 2292-2296)
Putting science and tech, or anything else, at the top of our priority list, is a bad idea. That's where God belongs. (Catechism, 2112-2114)
Somewhere around the mid-19th century, some folks decided that since we were learning quite a bit about how stuff works: God doesn't exist. I've over-simplifying the situation, of course. Remarkably — or maybe not so much — some Christians agreed.
We've been dealing with that mess ever since. (July 15, 2014)I can sympathize, slightly, with folks who feel flustered when the science they learned in school gets updated: or when a newly-found facet of reality doesn't match our preconceived notions of what's true.
However, when what we've 'always known' about the pillars beneath Earth or celestial spheres turns out to be wrong: that's our problem, not God's. (October 3, 2014; August 7, 2015)
If we don't insist that our preconceived notions are the only possible explanation, keep looking at the facts, and use our brains, sooner or later we'll understand:
"...God, the Creator and Ruler of all things, is also the Author of the Scriptures - and that therefore nothing can be proved either by physical science or archaeology which can really contradict the Scriptures. ... Even if the difficulty is after all not cleared up and the discrepancy seems to remain, the contest must not be abandoned; truth cannot contradict truth...."We're created by God, designed with a thirst for truth and for God. (Genesis 1:26, 2:7; Catechism, 27)
("Providentissimus Deus,"1 Pope Leo XIII (November 18, 1893) [emphasis mine])
We're made from the stuff of this world, and "in the image of God:" creatures who are matter and spirit. Using our senses and reason, we can observe the world's order and beauty: learning something of God in the process. (Genesis 1:26; Catechism, 31-35, 282-289, 355-361)
Bottom line? Thinking is not a sin. (March 29, 2015)
1. Pluto's Moon Kerberos: Answers Raise New Questions
(From NASA/JPL-JHU/SwRI, via BBC News, used w/o permission.)
("Kerberos has a double lobe shape and may be the result of a coming together of two objects
(BBC News))
"Pluto's moon Kerberos finally shows itself" Jonathan Amos, BBC News (October 23, 2015)Earth's moon is quite dark, only a little brighter than worn asphalt. Our moon's albedo, how much light it reflects, is 0.136 — it reflects 13.6% of our sun's light, on average. It's a lot brighter at the full moon, thanks to the opposition effect of rough surfaces.
"An image of Kerberos, one of the two tiny moons of Pluto, has finally been returned by the US space agency's New Horizons probe.
"It shows the object to have two lobes, which may be the consequence of icy bodies bumping into each other and joining up.
"Kerberos's larger lobe is judged to be about 8km across. The smaller lobe is roughly 5km in diameter.
"Styx, the other little moon in the system, is of a comparable size.
"Mission scientists say these satellites are brighter than they expected. Planetary bodies usually darken over time as a result of chemical changes triggered by sunlight and cosmic ray impacts.
"But these moons reflect about 50% of all incident light, which indicates their water-ice covering is very clean...."
Folks at NASA and JPL-JHU/SwRI squeezed as much information as the could from New Horizon's data — deconvloving and oversampling the image by a factor of eight. (NASA)
Those are words you don't run into every day. I don't, anyway.
NASA says that Kerberos is roughly 7.4 miles, 12 kilometers, across and 2.8 miles, 4.5 kilometers, wide. (NASA)
After color images from the Spirit Mars Rover, like that one, taken June 3, 2004; and results from soil analysis by the Curiosity rover in Gale Crater; a pixelated image of Kerberos may not seem impressive.On the other hand, we didn't know Kerberos existed before June-July 2011, when the Pluto Companion Search Team found it in Hubble Space Telescope images.
They were mostly looking for rings around Pluto, so the New Horizons flyby wouldn't end with a high-speed collision.
Now that we know roughly what Kerberos looks like and how big it is, we've got at least one more new puzzle to solve: what's it made of? Its surface may be ice, like Charon's is (probably), which would explain why it's so bright.
But Kerboros probably isn't ice all the way through.
Kerberos: There's More to Learn
(From NASA/JPL-JHU/SwRI, via BBC News, used w/o permission.)
("Charon (at bottom) is by far the biggest satellite in the system with a diameter of 1,212km"
(BBC News))
"Last of Pluto’s Moons – Mysterious Kerberos – Revealed by New Horizons"Maybe scientists will discover that Kerberos doesn't have as strong an influence on the other Plutonian moons as they thought: that's assuming that there's an error in the data or the math used in the original work.
New Horizons News, Johns Hopkins University Applied Physics Laboratory (October 22, 2015)
"...Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to 'weigh' Kerberos by measuring its gravitational influence on its neighboring moons. That influence was surprisingly strong, considering how faint Kerberos was. They theorized that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material. But the small, bright-surfaced, Kerberos now revealed by these new images show that that idea was incorrect, for reasons that are not yet understood...."
Or maybe there's another, not-yet-discovered, satellite that's causing the observed effects on the other moons' orbits. That, I think, is less likely: although an "invisible moon" would be very cool.
Or maybe Kerberos isn't ice all the way through. It wouldn't take a very thick coating to make it look the way it does.
I haven't found an informed discussion of the 'Kerberos influence,' so I've no idea whether that moon would have to be mostly rock, lead, or something unreasonably dense, to have the effect it apparently does.
The New Horizons team had the spacecraft fire its hydrazine thrusters for 16 minutes on October, the first of several maneuvers to send it to a flyby of 2014 MU69. That'll happen January 1, 2019. (NASA)
The BBC News article points out that NASA hasn't formally announced that it will have money for ground controllers. Whether there'll be anybody in mission control depends partly on the American Congress.
More:
- Wikipedia
- New Horizons
NASA- Last of Pluto's Moons – Mysterious Kerberos – Revealed by New Horizons
Tricia Talbert (October 22, 2015)
- Last of Pluto's Moons – Mysterious Kerberos – Revealed by New Horizons
- New Horizons
The Johns Hopkins University Applied Physics Laboratory
2. "Liquid Water Flows on Today's Mars"
(From NASA/JPL-Caltech/Univ. of Arizona, used w/o permission.)
(Dark narrow streaks coming from the walls of Garni Crater on Mars. Scientists made this model from observations by the High ResMars Reconnaissance Orbiter (MRO)'s High Resolution Imaging Science Experiment (HiRISE).)
"NASA Confirms Evidence That Liquid Water Flows on Today's Mars"
Guy Webster, DC Agle, Jet Propulsion Laboratory, Pasadena, California; Dwayne Brown,Laurie Cantillo, NASA; NASA/JPL News (September 28, 2015)
"New findings from NASA's Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.
"Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times...."
Before a mercifully-brief discussion of lineae containing hydrated chlorate and perchlorate salts and similarly-nerdy stuff — I'll show this rousing image of a green Martian on his thoat, and why the Guzman Prize2 excluded Mars.I remember the mix of excitement and disappointment when Mariner 4 sent back images of craters when it passed by Mars. (January 2, 2015)
Burroughs' Barsoom was entertainment. I'm pretty sure that nobody seriously expected to find such a literally-colorful array of folks living on Mars.
But the idea that we had neighbors living on Mars was taken seriously in the late 19th century — to the point that the Guzman Prize specifically excluded communication with Martians, since that didn't seem like much of a challenge.
Time ran out on the original Guzman Prize in 1910.
As we learned more about Mars, hopes of finding Martians dimmed. Most astronomers couldn't see Percival Lowell's canals and oases, and were skeptical about Lowell's story of a high-tech civilization struggling to survive on a dying world.
That version of Mars made a dandy setting for tales of high adventure and intrigue, though, and that's another topic.
By the mid-20th century, scientists had lowered their hopes and expectations from finding people to finding moss and lichens on Mars. (July 24, 2015; March 13, 2015; January 24, 2014; October 17, 2013)
Remembering Mariner
Mariner 4 made the first successful Martian flyby on July 14 and July 15, 1965.Like other folks who had been paying attention, I didn't expect to see equivalents of Barsoomian Gathol or Helium.
But I'd hoped for something other than craters.
Martian air wasn't a vacuum: but 4.1 to 7.0 millibars, 410 to 700 pascals, is about four to seven thousandths of Earth's sea level pressure.
Scientists figured daytime temperatures were around −100 degrees Celsius. They found no magnetic field or Martian radiation belts.
The Mars Mariner 4 found seemed only marginally more hospitable than our moon.
Then Mariner 9, Mars 2, and Mars 3 went into orbit around Mars: arriving in time for a planet-wide dust storm.
Channels on Mars
(From NASA/JPL-Caltech, used w/o permission.)
(Nirgal Vallis, Mars; image from Mariner 9, 1971.)
When the dust settled, we started getting a more comprehensive look at the surface: including places like Nirgal Vallis, a channel 496 kilometers long.
Scientists are still debating exactly what's happening on Mars, and how Martian features that look like river channels and deltas formed.
It's possible that something other than flowing water cut the channels and deposited the deltas. My guess is that when something walks and quacks like a duck, it's probably a duck — and that Mars hasn't always been as dry as we thought it was after that first Mariner flyby.
There's fairly good reason to believe that lakes formed in the Hellas and Argyre basins; Gale, Holden, Ritchey, Jezero, and Columbus craters; and elsewhere on Mars.
More:
- NASA
- "NASA Confirms Evidence That Liquid Water Flows on Today's Mars"
press release (September 28, 2015) - "NASA Research Suggests Mars Once Had More Water Than Earth’s Arctic Ocean"
press release (March 5, 2015)
- "NASA Confirms Evidence That Liquid Water Flows on Today's Mars"
- Wikipedia
- "Nepali Scientist Lujendra Ojha spots possible water on Mars"
Pradeep Singh, NepaliBlogger (August 6, 2011)
Evidence
"Evidence for recent flows," that last bit from Wikipedia, talks about followup on Lujendra Ojha's research. He's the Nepalese undergraduate student who noticed those darkish streaks, recurrent slope lineae, that show up on some Martian slopes during the warm season. That was in 2011.The streaks could have been made by salty water flowing downslope and evaporating. Then again, something else could be making them.
Having a plausible idea is one thing. Having data to back it up: that's where this year's announcement comes in.
The Mars Reconnaissance Orbiter's CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) made direct observations of hydrous salts appearing where and when the streaks show up.
Looks like the linae contain hydrated chlorate and perchlorate salts. Perchlorate salts come from perchloric_acid, stuff that's useful but not particularly safe when mishandled.
Salts, for a chemist, are ionic compounds that happen when an acid and base cancel each other out. They're made of related numbers of positively charged ions and negative ions, so they're electrically neutral. Sodium chloride is what most folks mean when they say "salt," and that's yet another topic.
One more thing: these dark streaks form during Martian summer, when the temperature is above -23° Celsius or -10° Fahrenheit. Assuming the stuff that's flowing is water, it's probably the hydrated chlorate and perchlorate salts that keep it liquid. We still don't know where the water comes from.
More posts about "wonderful things:"
- "Organics on a Comet, and Earth's Early Magnetism"
(August 7, 2015)
Particularly - "Pluto, Earth 2.0, and Life in the Universe"
(July 31, 2015)
Particularly - "Alien Worlds, Martian Methane, Looking for Life"
(January 2, 2015)
Particularly - " 'Organic,' 'Wow!' — and Double Planets"
(November 28, 2014)
Particularly - "Harpooning the 'Rubber Duck' Comet; Public Safety — and Space Aliens"
(November 7, 2014)
Particularly
1 Lord Carnarvon's account of discovering Tutankhamen's tomb on December 10, 1922. Quote from "Howard Carter before Tutankhamun," Nicholas Reeves, John H. Taylor (1992); via Wikipedia.
2 The the French Académie des Sciences announced the Prix Guzman, or Guzman Prize, in 1900. 100,000 francs would go to the first person or nation to discover how to communicate with a star — presumably folks living in the vicinity of a star — and receive a reply. The original prize had a 10-year deadline.
Wikipedia explains that communicating with Mars wouldn't count, "as many people believed that Mars was inhabited at the time and communication with that planet would not be a difficult enough challenge."
The prize was sponsored by Clara Gouget Guzman, in honor of her son Pierre. Pierre Guzman had been interested in Camille Flammarion's work including "La planète Mars et ses conditions d'habitabilité" ("The Planet Mars and Its Conditions of Habitability,) 1892).
3 comments:
I think there's an incorrect word tense in here: "Before a mercifully-brief discussion of lineae contain hydrated chlorate"
The Friendly Neighborhood Proofreader
You're quite right, Brigid! Found, fixed, and thanks!
Thank you for this info
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