Thermal structure of Hurricane Maria

Sep. 22nd, 2017 03:35 am
[syndicated profile] flowing_data_rss_feed

Posted by Nathan Yau

Hurricane Maria touched down in Puerto Rico. This visualization by Joshua Stevens at NASA shows what the thermal structure of the storm looked like, based on data collected by the Terra satellite.

Colder clouds, which are generally higher in the atmosphere, are shown with white. Somewhat warmer, lower clouds appear purple. The image reveals a very well-defined eye surrounded by high clouds on all sides—an indication that the storm was very intense.

Ugh.

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sovay: (Sovay: David Owen)
[personal profile] sovay
Even if the rest of the film were forgettable, Howard Hawks' Red River (1948) would be worth it for the climactic fight scene where Montgomery Clift and John Wayne are tragically and brutally and patriarchally beating one another's brains out and just as the audience, consisting in this case of me and [personal profile] rushthatspeaks, decides they cannot take another second of this senseless macho bullshit, Joanne Dru can't either and not only says as much, she holds both combatants at gunpoint until they cut the machismo and admit they love one another. It was a thing of beauty. ("You'd better marry that girl, Matt.") Factor in the gun-comparing scene between Clift and John Ireland and other not infrequent moments of no heterosexual explanation and the whole thing was a nice break from today's otherwise relentless grind of paying work, even if we weren't totally sure at points. It is not easy to watch a movie in the company of an active and eventually tired and cranky eleventh-month-old, but we managed. In other news, Fox these days is freestanding, fast-moving, can hang upside down by the knees if an adult holds them, and appears to be taking against the entire concept of pants. They like honeycake, though.

Autolycus is being heartbreakingly plaintive right now. He has a vet appointment early in the morning and it requires fasting, which is an impossible concept to explain to a cat. I let him graze all day and gave him a proper dinner at the absolute last moment, but he is attempting to convince me that, actually, in point of fact, he starved since then. We should find him some kind of special treat after the appointment, for being so brave and honest. Last night he and his sister shared in the Rosh Hashanah chicken. All cats are lunisolar.

In honor of the High Holidays, here is a post on Jewish superheroes and here is a brilliant riposte to the rather short-sighted question "How can you be Black and Jewish?"

Back to the relentless grind. At least it is almost autumn.

spring is in

Sep. 22nd, 2017 09:44 am
tielan: (don't make me shoot you)
[personal profile] tielan
I have my hockey presentation night tonight, but due to a blood test, I can't eat anything and shouldn't drink anything but water after 10pm. Which is not entirely a bad thing because I don't actually feel like socialising tonight. Set INTROVERSION to ON.

I want to go home tonight and write; and then tomorrow I want to do ALL THE PLANTING AND GARDENING.

Well, going to re-roof, um...

Sep. 21st, 2017 11:17 pm
archangelbeth: Bleach's Captain Byakuya, three-quarters view. Captioned: sigh (Sigh)
[personal profile] archangelbeth
Lessee, about a third of the house? The garage and the triangle of the roof on the Main Part that faces the garage, and probably some re-siding, since they're gonna put a rubber membrane all over everything to keep the ice dams from happening again and overflowing the protective plastic and coming in and WRECKING THE HOUSE AGAIN.

There will also be a hatch into the dead-space behind our bed/closet, where the flying squirrels were living. They are gonna be maaaaaad.

I cracked open a lot of chestnuts. Chestnuts are what happen when artichokes and oak trees interbreed.
https://twitter.com/emccoy_writer/status/910954038417600512
(It's all soft and fluffy in the very inside, like the very center of an artichoke...)

None of the chestnuts I found were round enough to be likely to be fertile, darnit.

Havva Quote
[more on Norsemen, a show...]
f___ stares in a certain amazement at some of the dick jokes they've decided to go with here.
-----------------------Quoted by f___-----------------------
1: "You still have that huge farm? Mm, and it's going well? Lovely, and, uh, yes. And I've always really respected you, so, uh, I'm going to challenge you to a holmgang."
2: "...what?"
1: "Yes, where, uh, the winner takes all the property of the loser, and his land, and his wife, and, uh, so forth. That's the rules, isn't it?"
3: "Yes, yes, that's right."
2: "...but you have no property! And I worked to build up all of this!"
1: "Yes, uh, that's true, but those are the rules, and it would be very foolish of me not to take advantage of that, wouldn't it? I've always really respected you. So, uh, yes. I challenge you to a holmgang. I don't make the rules."
Room, chanting: "HOLMGANG. HOLMGANG. HOLMGANG."
------------------------------------------------------------
-----------------------Quoted by f___-----------------------
Omar's wife: "Omar? Omar? Are... are you hiding?"
Omar: "I'm just thinking! In private!"
"You can't avoid the holmgang, you'll shame yourself, and me. Indirectly."
"It's just that... Arvid is so big, and he's trained to be a warrior since he was a baby, and he's probably killed a thousand men. I've never touched a sword before today!"
"Blah, blah, don't be so defensive. You can beat him. It's all in the mind. 99% attitude."
"...is it?"
"Sure. If you raise your game 5%, and he lowers his 5%, most of the job is done."
"Are the margins that... uh... small?"
"Sure. And if you admit the possibility of thinking a little bit outside of the box, anything could happen, hm? Okay. Good luck. See you there."
------------------------------------------------------------


INwatch+Bookwatch )

Dragons under fold )

iPods

Sep. 21st, 2017 10:53 pm
james_davis_nicoll: (Default)
[personal profile] james_davis_nicoll
Haven't been around long enough for an adult to reference the technology as something around when they were kids. That's just crazy talk -- 16 years ago, you say?

yuletidings of affection and joy

Sep. 21st, 2017 09:51 pm
ar: "It's a lot easier to tell the truth usually." - Elliott Smith (Default)
[personal profile] ar
Dear Christmas Bale,

This is AR, aka Who Shot AR (akerwis) on the AO3.

IDK about you, but man, Yuletide sneaked up on me this year. But I'm excited to be here, and I'm excited for both of us to have a great season! I've provided deets below for you, both on my general interests and my fandom-specific ones, but I want you to know that the number-one thing I want most is for you to have a fun time writing a story. This letter exists as some quietly excited ideas for you, but your own excitement and creativity are what make Yuletide wonderful, and I trust you to use this nonsense here as much or as little as you'd like. Please follow your heart where it takes you.

So, the general stuff:

Yes, please: All tenses and POVs, afterlife stories, arguments and apologies, bittersweet stories, character deaths, children, clothing descriptions, complicated relationships, confessions of love, diary fiction, domesticity, epistolary fiction, fairy tales, fairy tale retellings, family stories, femslash, flowers, fluff, food descriptions, friendship, gen, ghosts, grief, hand-holding, happily ever afters, haunted houses, het, holiday stories, Hollywood amnesia, hopeful endings, huddling for warmth, magic in the real world, mentorship, one-sided crushes, parenthood, pastiche, period settings, poetry, popular music, pregnancy, realistic fiction, recovery from failure, religious themes, sad but appropriate to the rest of the story endings, sensory details, snowstorms, sweet stories, this Venn diagram, traditions, tragedies, unusual formats, wingfic, zithers. :)

No, thank you: Alien abductions or grey alien types, asexual headcanon, autism headcanon, cats suffering even mild inconvenience (I can handle all other animals being in danger / dying / getting dinner two minutes late, but I'm really sensitive about cats), issue fic, poly shipping, religious bashing, storylines ripped from current US political headlines, trans headcanon, unrelenting cynicism

Here are my old letters, if those might help you. Please forgive any copy-pasting I've done from year to year--I'm afraid I get lazy at times!

-Yuletide 2016
-Yuletide 2015
-Yuletide 2014
-Yuletide 2013
-Yuletide 2012
-Yuletide 2011
-Yuletide 2010
-Yuletide 2009

And this is my general Yuletide tag, which might be of interest to you but might also just be kind of nonsense-y.

Nota bene: While there might be some variance in the length of my tl;dr under each request, please be assured that I want all these requests with equal fervor. Some of my requests are less wide-open than others, or involve significantly less canon, so they take fewer words to explain. ♥ If, in any of these situations, you feel like I haven't given you enough to work with, please reach out to me so I can type some more excited nonsense to you!



the ramsay scallop; elenor of ramsay, thomas of thornham )

doctrine of labyrinths; methony feucoronne )

kavclay: rosa saks, thomas kavalier )

uncanny x-force: evan sabahnur, fantomex )

all new x-men: evan sabahnur )

That's everything I've got for this year. I hope this was a manageable read for you, and again, please don't stress the details. I have faith that you'll come up with something marvelous. Please feel free to reach out through the mods if you have any questions for me--or, if you need an answer on the double, please feel free to comment anon here on my letter. I'm not bothered either way.

Thank you for your kindness and generosity, and I hope the end of your year is a pleasant one. You have all my best wishes as we jump into this fest together.

Yours,
Who Shot AR (akerwis)
[syndicated profile] pharyngula_feed

Posted by PZ Myers

Pity poor Jon Del Arroz! The sad far-right science fiction author first came to my attention a short while ago when he was complaining bitterly that the SJWs had taken over science fiction, using cherry-picked and misleading statistics. He’s got a persecution complex big enough to fill the San Francisco bay, where he lives.

Now he’s getting picked on again! He claims to have been blackballed from a local convention — he’s spoken there before, but he was not invited this year. After going on and on about reviews for a recent book, and praising himself mightily, he cuts to the chase.

The reason I was disinvited was because it is well known that I support the President of the United States, duly elected and all, and that I’m happy about the way the country is being run. You know, like most normal people are. That’s the only thing that’s changed between then and now. It’s the same dangerous rhetoric out there that many of these folk who run the convention post on such a consistent basis that has turned Facebook from a “fun catching up with friends” website to a hellhole of fear, anger and hate (which as Master Yoda taught us, leads to suffering!). It’s impossible to communicate anymore, and as such, there is a small but vocal power structure of people in the convention scene and publishing that can’t tolerate the concept of seeing my pretty face. I am a minority that’s been discriminated against, not because of my race, but because of my ideas. In Science Fiction, ideas are everything, and it’s frightening to think about those being shut down as a consequence. These people want my career to fail, and they believe they can accomplish that by silencing me and giving me the cold shoulder.

There’s one little problem with this woeful narrative. We have the letter the conference organizers personally wrote to him after he complained.

Dear Jon,

Thank you for your interest in BayCon 2017. We have made some changes to the programming which are discussed in detail here: http://baycon.org/bcwp/programming-2/

At this time we are not issuing you an invitation for this year’s convention. You are definitely on our guest list for 2018 and we hope very much to see you there.

Sincerely,

BayCon Programming

He wasn’t blackballed. He’s even on their list for next year. They just like to rotate their speakers a bit, and not bring in the very same people every year — which is a good policy. I like hearing from new people.

Jon Del Arroz thinks getting one invitation to speak means he is now invited to speak at every con every year in perpetuity. He’s an idiot. He’s such an entitled ass, I have to wonder about BayCon — why have they invited him back for next year? Have they no standards in invited speakers? That’s not a good sign.

By the way, I have a similar example: I was a speaker at Skepticon multiple times. One year they decided they needed new blood, so they invited some other people, instead of me. If I were like Jon Del Arroz, I would have made a big stink over the violation of tradition — they invited me once (actually, a couple of times), so now they must invite me every time. Every year. Over and over. Until attendees are sick of me, and even then they aren’t allowed to stop.

That isn’t the way this works. I approve of diversity in the line-up. I think it’s great that they have enough people with interesting things to say that they can have a different roster of speakers every year. I’m perfectly willing to step aside, especially since it means I can just attend and enjoy the event without having to give a talk.

But then, I didn’t vote for Donald Trump. Maybe it’s all those rabid Republican dude-bros who run Skepticon who have blackballed me.

[syndicated profile] pharyngula_feed

Posted by PZ Myers

The University of Minnesota, Morris biology discipline has been approved to fill a tenure track line in biology. Here’s the description:

The University of Minnesota, Morris Division of Science and Mathematics seeks an individual committed to excellence in undergraduate education, to fill a tenure-track position in biology beginning August 20, 2018.

Required/Preferred Qualifications:

Required: Applicants must hold or expect to receive a Ph.D. in molecular biology or related field by August 20, 2018. Experience and evidence of excellence in teaching and mentoring undergraduate biology students is required (graduate TA experience is acceptable.)

Preferred: Preference will be given to applicants who are able to develop and teach upper-level elective courses in their area of expertise and which complement those offered by the current biology faculty. Applicants with expertise in quantitative approaches to molecular-scale data are strongly encouraged to apply.

About the Job

Duties/Responsibilities: Teaching undergraduate biology courses including introductory biology, molecular biology with lab, electives in the applicant’s areas of expertise, and other courses that support the biology program; advising undergraduates; conducting research that could involve undergraduates and potentially in collaboration with our data sciences faculty; and sharing in the governance and advancement of the biology program, the division, and the campus.

This tenure-track position carries all of the privileges and responsibilities of University of Minnesota faculty appointments. A sound retirement plan, excellent fringe benefits and a collegial atmosphere are among the benefits that accompany the position. Appointment will be at the Assistant Professor level for those having the Ph.D. in hand and at the Instructor level for those whose Ph.D. is pending. The standard teaching load is twenty credit hours per year.

As a small university, note the teaching requirements: we need someone to help teach molecular biology, so wet lab experience is important. Molecular biology is an awfully broad category, though, so also note the buried detail: “Applicants with expertise in quantitative approaches to molecular-scale data are strongly encouraged to apply.” The magic word there is “quantitative”. We’re looking for someone who applies quantitative analysis to their work. We’re wide open to a lot of different approaches. Are you a bioinformatics person who is analyzing the evolution of specific genes? Lovely. Are you a systematist studying plant taxa with quantitative techniques? Go for it. Looking at biomechanics? We don’t do that here, but it would be cool to have it. We just hired a big data guy in computer science and statistics, so being able to work with that field is a big plus. Help us add a deeper mathematical element to undergraduate education.

Why should you apply here? We’re on the western prairies of Minnesota (no, we’re not located in Minneapolis/St Paul, so don’t think we’re a big city place) and kind of remote — if you like small town life, it’s a great place to be. Our university strongly emphasizes a quality education, personalized and supportive, so if teaching is your bag, we want to hear from you.

Shorter summary: we are looking for a biologist who likes math and teaching. Come join us!

Back home and back to school

Sep. 21st, 2017 02:38 pm
silailo: (mingchao pale)
[personal profile] silailo
Wow wow wow, I haven't posted in a long time.

Last weekend I moved back home and yesterday I started school. I had to unpack as much as I could before classes, so I was super busy.

A lot has changed in the anthropology department since I was there last. I knew there had been changes, but I didn't know the extent. A lot of teachers have retired, mostly in the geography department (we are actually considered a single department, though). I don't know any of the students, except one guy I graduated with is lurking around somewhere because he's finishing up his Master's thesis. Classrooms have changed with new desks and whatnot, and others have been cleaned out from all the junk that had been stored in them for years.  Although the school is slowly rebuilding/remodeling the buildings on campus, I doubt the anthropology-geography building will be done any time soon, so I think they're trying to do what they can to make improvements. It looks pretty nice, in my opinion.

I don't have much homework yet, which I'm glad for because I want an easy weekend. ^^; I am really not excited about homework again.
rolanni: (Default)
[personal profile] rolanni
If you have read Neogenesis and want to talk about it, this is the link to the spoiler discussion.
rolanni: (Default)
[personal profile] rolanni

For them what indulges, the eARC of Neogenesis, by Sharon Lee and Steve Miller -- the 21st Liaden Universe®! -- is now available for download (and reading, natch).

Get yours here!

I will, in the fullness of time, set up a spoiler page at sharonleewriter.com

English suites no. 1

Sep. 21st, 2017 01:55 pm
calimac: (Haydn)
[personal profile] calimac
This has been Gustav Holst's birthday, as the radio announcer kindly informed me, so it's as good a time as any to use a Holst work to launch a musical project I've been mulling for some time, which is a series of pleasant, mostly modern, suites, first by English composers and then branching out.

This is probably the best-known one I'll be presenting in the entire series, Holst's St. Paul's Suite. It's played by a student orchestra from Poland, which might account for the unusual sonority. The players are all female, appropriately, as Holst wrote the work for the students of the St. Paul's Girls' School, where he taught music for many years.

Like many of the suites to come, it's in four movements vaguely replicating sonata form, and the finale, as with many of Holst's best works, incorporates a sturdy old English folk tune.

winkychan: (Default)
[personal profile] winkychan posting in [community profile] arashi_off
Hi!

We're [livejournal.com profile] arashiproject  and we work in reuploading the dead subbed files made by old subbing teams, in the respect of their rules.

We have opened 2 new masterposts for [livejournal.com profile] niji_no_sekai  and [livejournal.com profile] tenjostyle  + [livejournal.com profile] nyanchan  you can read everything in this entry.
Please treat yourself with what has been reuploaded and if you have any of the missing files, don't hesitate to help us reupload them ^^

Membership is moderated, just click join and wait for approval.

Thank you for your help and support :)

Transitions....

Sep. 21st, 2017 03:36 pm
captainsblog: (Default)
[personal profile] captainsblog
More or less chronological from the past day:

Our longtime neighbor's house is finally up for sale. The sign went up late yesterday, and a listing showed up this morning.  By this afternoon, the listing realtor's site for it had been taken down. Did it sell that fast, or is something else going on?  This third-party site still has the info and some photos of in and out:



Yup, it's the answer to life, the universe and everything!



All traces of Betty's gardens are gone.



A retro-fan friend of mine picked right up on the built-in radio, likely of the same vintage as the '57 Buick of a built-in oven we still have in our kitchen next door.

Anyway, all this can be yours (including the curtains). Unless it can't because it sold in under a day- which does happen around here these days.

----

Also last night, before I saw any of those pictures, I saw this one:



A friend and fellow aminal lover posted this tale from the City of Buffalo Animal Shelter:

 

Lilly is a 12-18 month old chocolate lab mix who came to the shelter when her owners moved out of their house and left her behind. A concerned neighbor brought her to our care.

REALLY?!? Who does that? She looked well cared for, and the rest of the listing said she was doing well meeting people and other dogs.  I knew the time was all wrong- with Eleanor's three month layup, she's going to have enough trouble letting one dog out the back door during the day- but cmon. That FACCCCCE.  So I detoured after court this morning and checked. Sadly (or happily, really), Lilly already got adopted out. There were plenty of other choices, most of them pitties, but no. This would have been for Tasha- our first doggie rescue, a Chocolate lab mix who we gave the best 12 years of her 13 years of life through a few years ago. I'll continue to say no, but I'll never say never.

----

In other transitions, a longtime friend lost her longtime cat companion the other day. But not many Rainbow Bridge residents have a whole series of mystery novels starring them for us to remember them by:



Closer to home, the longtime companion of a former coworker passed away this week after a very long series of end days. His funeral is Saturday morning, and I think I need to go to that.

----

I think I also need to go out of town tomorrow for my only trip this week.  Nothing about THAT ever changes.
[syndicated profile] pharyngula_feed

Posted by PZ Myers

As a measure of the degeneration of our public discourse, all you have to do is turn on your TV, and you’ll find a whole sequence of corrupted discussion. It’s not just Fox News; the people who credulously watch Fox may also find themselves primed by the so-called “educational” stations, the ones people watch because they’re supposed to make learning interesting by explaining stuff that people are already curious about. Somewhere along the line, though, the television programmers realized that you can just drop the difficult “education” part and skip right from “curiosity” to “spectacularly batshit looney-tunes stories from grossly unqualified (that is, cheap) sources”. Take The History Channel, please.

I don’t know if you knew, but the Hebrews didn’t spend forty years in the Sinai after the Exodus because they’d incurred the wrath of God. And they didn’t leave that desert because the offending generation had died off. The chosen people were forced into the Promised Land because the algae-based-protein-bar machine that dispensed the “manna from heaven” they’d been eating finally broke down.

“Of course, [the machine] needed energy, for cultivating the algae, and this was produced, we postulate, by a small nuclear reactor,” says Rodney Dale, a wild-eyed madman.

This is the History Channel, circa 2009. “But,” asks the narrator, “If the Israelites’ survival depended upon the manna machine, where did they get it? Some believe they had stolen it from the Egyptians prior to their exodus. Other suspect extraterrestrials gave it to them as a humanitarian gesture to prevent their starvation in the desert.” The show is “Ancient Aliens,” and it’s everything that’s wrong in America.

I haven’t watched it in years, since it gave up on History and decided that people driving trucks or others buying crap at auctions was more interesting, i.e. profitable. It seems to be oscillating between the mundane, like pawn shops, and absurd bullshit, like aliens building portals in the Southwest desert. The only thing worse than an occasional television show with unbelievable claims is to actually attend a conference by these true believers — I’ve gone to the Paradigm Symposium twice now (and never again), and you discover very quickly that sensational, exaggerated claims without plausible evidence are deeply boring. That’s happened to the History Channel, too — it’s boring, and they try to reinvigorate it by making more and more ridiculous claims. It doesn’t work.

Oh dearie me, this guy's got form

Sep. 21st, 2017 08:41 pm
oursin: Cod with aghast expression (kepler codfish)
[personal profile] oursin

Back in 2008, Gandhian pilgrimage that ended at Calais.

And his present (surely it is the same guy) simple life agenda has crossed my horizon heretofore.

My dearios, I give you I live a healthier life now I’m free of the trappings of modernity.

O, lucky old you, a healthy bloke with sufficient resources to undertake this project and pontificate about it. You are not just lucky to be 'born without any serious long-term health issues' - this is due to various factors including maternal nutrition and antenatal care, vaccination against common childhood diseases (even if he didn't get these, and I bet he did, he would have benefitted from herd immunity), i.e. the benefits of modern medicine and sanitation.

Also, I have no time whatsoever for anyone who dismisses other people's experiences of pain: there is a man who, we must suppose, never sat an exam while doubled over with period pain, or suffered a migraine. Not at all rare conditions. Your body is not 'always aiming for balance and health'.

And we observe that he has had a vasectomy... because one of my questions (among the many stimulated by the thought of all the technological advances that have made women's lives so much less arduous, which I remarked on when his bogosity first impinged upon my aghast gaze), wot abaht contraception?

Perhaps we might introduce him to the notion that being regularly flogged with a large codfish is a cure for pretentious woowoo?

(And do we think that his simple austere life is 'more work for other people', like the process that gets his handwritten ms - written on tree bark in berry juice, we wonder? - from his simple cabin in the woods to the Guardian website?)

[syndicated profile] badastronomy_feed

Posted by Phil Plait

On the morning of Friday, September 22, 2017, the Earth will experience a close encounter with a spaceborne object. But never fear! We’re perfectly safe. That’s because the space traveler is the NASA probe OSIRIS-REx, and it will pass more than 17,000 km above the Earth’s surface.

The flyby is designed so that the spacecraft will steal a little bit of the Earth’s orbital energy, using it to fling itself up, changing its own orbital plane to match that of its target, the asteroid Bennu. OSIRIS-REx will pass closest over Earth’s south pole, and the Earth’s gravity will naturally bend the probe’s path up, up, and away.

This is the third event in the mission’s life in space, counting launch as the first. It launched a bit over a year ago and was placed into an orbit similar to that of Earth around the Sun. In January 2017 it performed a “deep space maneuver,” firing its engine enough to change its velocity by about 1600 kilometers per hour, putting it on the correct course for the flyby.

If you want the details of this flyby, then (as always) you should check in with my friend Emily Lakdawalla at The Planetary Society, who has the info.

The spacecraft has already been spotted by Earthbound telescopes; the Large Binocular Telescope in Arizona saw it on September 2:

Animation showing the movement of OSIRIS-REx on September 2, 2017, when it was still 12 million km away. Credit: Large Binocular Telescope Observatory

Animation showing the movement of OSIRIS-REx on September 2, 2017, when it was still 12 million km away. Credit: Large Binocular Telescope Observatory

I know, it doesn’t look like much, but c’mon: It was 12 million kilometers away and at a magnitude of 25. The faintest star you can see with your naked eye is 40 million times brighter! So this is actually pretty good.

If I’ve done the math right, it’ll be roughly magnitude 11 or so when it passes Earth on Friday. That’s still faint, though within reach of a good telescope. The mission web page has advice and links for trying to see it. Given how far south it’ll be, that means it’s easiest from southern locations; in Australia the Desert Fireball Network will use the flyby to test out their cameras. They’ll observe OSIRIS-REx from different locations and use that to get its 3D trajectory in space. They use the same technique to track material like meteors burning up in Earth’s atmosphere.

I mentioned three events in the mission’s space life so far, but the fourth event is the big one: arrival. Approach starts in August 2018, when OSIRIS-REx is about 2 million km from Bennu. It’ll begin a series of engine burns to slow its approach relative to the asteroid until it goes into orbit. Starting on October it’ll begin surveying Bennu, and will continue to do so for a year.

The orbit of Bennu (blue) is similar to Earth's. This shows their relative positions on the day of the OSIRIS-REx flyby. Credit: NASA / JPL

The orbit of Bennu (blue) is similar to Earth's. This shows their relative positions on the day of the OSIRIS-REx flyby. Credit: NASA / JPL

Bennu is a pretty interesting asteroid (if it weren’t, then duh, we wouldn’t be sending a spacecraft to it). It was discovered only in 1991, and is on an orbit similar to Earth’s, though slightly bigger, more elliptical, and tilted to ours by about 6°. That’s a substantial inclination, taking a lot of energy to match, which is why the spacecraft is using Earth to whip it around. Bennu only approaches Earth about once every six years (its orbital period is about 1.2 years, so it takes a while for it and the Earth to sync up).

Bennu itself is about 500 meters across, a decent-sized chunk of rock (though it will be the smallest object NASA will have ever had a spacecraft orbit, an interesting statistic). It’s what’s called a B-type asteroid, meaning it’s rich in carbon as well as what are called volatiles: materials with low boiling points. Even though it’s small, it may have water inside it, trapped in materials like clays.

It’s shaped roughly like a top or a walnut, slightly wider than it is high. It rotates once every 4 hours or so. Its overall shape was determined from both radar mapping as well as how it changes brightness with time (for example, a very long object can get much brighter when it’s broadside to you, and fainter when it’s end-on). Interestingly, its mass is low; given its size it’s barely denser than water! It’s likely to be a rubble pile, a collection of loosely bound rocks held together by gravity and other forces. That can happen as an asteroid suffers low-speed impacts over billions of years, shattering it in place. Lots of voids form between the rubble, accounting for the low density.

Other than that, it’s thought that Bennu hasn’t undergone much change since it formed 4.5 billion years ago. It’s hoped to be a time capsule dating back to the formation of the solar system itself!

NASA made this spiffy short video explaining more about Bennu, OSIRIS-REx, and the mission itself:

Oh, one more thing for now: OSIRIS-REx is loaded with instruments to examine the asteroid, including cameras, LIDAR, and a spectrometer. But it also has another package: a sample return capsule (SRC). While at Bennu, it will collect a sample of surface material, squirrel it away inside the capsule, then send it back to Earth! This has been done by a mission before (the Stardust mission to a comet), so it’s tested tech.

Scientists want to collect at least 60 grams of material, though they might get more. The mechanism to collect the sample will puff nitrogen gas onto the asteroid surface and then collect the material that floats off. They have enough gas to try this three times, so it seems likely they’ll get what they need.

Then the SRC will be sent on its way back to our planet, arriving as a fireball in the sky and then falling to Earth in July 2020. It’ll be collected and the samples brought to labs where this pristine asteroid material can be studied in much greater detail than is possible with a spacecraft.

But that’s all still far in the future. First things first! Let’s get the flyby done, and then we can start looking ahead to seeing Bennu up close and personal next year.

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Artwork showing OSIRIS-REx flying past Earth above Antarctica and South America. Credit: NASA Goddard Space Flight Center/University of Arizona

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