mikewong's astroblog

Uploading multiple files from the command line using curl and the FTPS protocol

Sat 2022-06-11 14:02

I needed to upload a bunch of files to the MAST archive, but FTP is no longer allowed because it is not secure. The MAST announcement recommends "GUI clients Filezilla, Cyberduck," but I have a purely emotional response to this: I don't feel the maximum enjoyment of techie accomplishment if I have to click bubbles in a tool called Cyberduck. I want to use the command line, like I used to be able to with FTP.

The MAST announcement said you could use curl, but it didn't give a good example. I wanted a way to do the following:

Run on the command line.
Upload a whole bunch of files to a single directory.
Require typing password only once.

Basically, I was looking for the equivalent of typing mput hlsp_* in FTP. This is what worked for the MAST archive:

      curl --ssl-reqd -u USERNAME 
           -T 'hlsp_{dogs.txt,cats.fits,birds-and-worms.fits}'
           ftp://archive.stsci.edu/pub/MY_DIR/

--ssl-reqd creates an explicit FTPS connection rather than a FTP connection, as required by MAST security.

-u USERNAME tells what username that curl should send to the server (for this system it is our email address). You would be able to tell curl to also send your password by using -u USERNAME:PASSWORD, but I prefer to leave password blank so that I can enter it invisibly at the prompt.

-T 'hlsp_{dogs.txt,cats.fits,birds-and-worms.fits}' is the way to specify several files. I tried to use -T 'hlsp_*'. But that does not work, because curl is doing URL globbing, which doesn't support a * wildcard. URL globbing was designed to loop over a set of URLs following a pattern, not to loop over a set of local files.

ftp://archive.stsci.edu/pub/MY_DIR/ is the destination URL, and when uploading multiple files, this must end with a "/". Some testing suggests that for MAST, you can also start the URL with ftps:// and omit the --ssl-reqd option to perform the transfer under an implicit FTPS connection.

The rainbow collection.

Tue 2022-04-05 22:06

Here are some planetary science rainbow logos, in case anyone wants to use them for anything. I made stickers of the rainbow pixel-rover (based on one of the fiducial tattoos on Curiosity), so I can give you one if you see me in person. Maybe I'll do the worm next.

Today's rainbow-fest is inspired by reading the latest article in Scientific American about how NASA declined to remove James Webb's name from its flagship telescope. I already commented on this issue below, but check out the best new thing in this article: the quote from Scott Gaudi.

The article pointed me to a cool resource, the Astronomy and Astrophysics Outlist. I read through all 800+ names, which gave plenty of time for a swirl of thoughts:

Oh [him/her/them]?
Wow there's a lot of Berkeley.
Now that you mention it, duh.
Hm. This list is not complete.
All these people would have been fired 60 years ago.
That affiliation? This list has been around for a while.
So sweet that [he/she] took the time to sign the allies list !!
Sapphic can be an identity label? Neat.
Schools that have "research professors" are cooler than Berkeley.

The Klaus Teuber Space Telescope?

Fri 2022-01-07 14:50

My friend noticed that the segmented JWST primary mirror matches the segmented playing board of Settlers of Catan. ("The black thing in the middle is the robber," he said.)

NASA should rename the telescope after Catan creator Klaus Teuber. This would have double benefits: It would give proper credit and avoid a copyright infringement suit against NASA for blatantly copying the playing board. But more importantly, it would eliminate the telescope's problematic association with a bureaucrat who enacted anti-queer policies in NASA and the State department as part of the "lavender scare."

Actually the best choice — if NASA wanted to return to the convention of naming space observatories after scientists — would be renaming the telescope after Dr. Frank Kameny. Kameny actually lost his job due to anti-LGBTQ discrimination (although not while Webb was in charge of anything), driving him to leave science for activism. He was mentioned in the Scientific American piece that originally boosted the issue of James Webb's problematic associations.

Whatever its name, the telescope's job is to busily create infrared rainbows behind a lavender sunshield, making it possibly the gayest thing in space.

Using alpine as an IMAP client for G-suite at UC Berkeley.

Mon 2021-10-11 10:41

It's been 8+ years since my last post on how to keep ancient mail readers working with the most popular corporate email provider. The instructions there about encrypting your pine password file still work. But Google's "app passwords" can't be used any more at Berkeley, so here is the current method.

You need to have Alpine v2.22 or above. To trigger authentication with the currently-supported OAUTH2 method, use settings as shown above. I got this from the relevant page in Eduardo Chappa's Alpine project. You also have to go to console.developers.google.com and follow these helpful instructions from UMBC, which are far more complicated than the old procedure of creating an app password. There are also instructions for this part at the Alpine project, but the UMBC instructions are slightly easier to follow (and I found them first).

Now sometimes when you open Alpine, it will show a screen with an ugly Google link. Copy/paste that to a browser where you are logged in to your G-suite account, copy the key that the link provides, come back to Alpine, and enter that key after pressing "C" for "enter Code."

Python in a TI graphing calculator.

Fri 2021-07-30 11:36

I just saw an article/ad for a Texas Instruments TI-84 that has Python. This is so exciting and cool. This is what I want for Christmas, even though I'm pretty sure I would not actually use it. I made a whole pros/cons list to understand how completely irrational my attraction to this device is:

Pros	Cons
Cool Has Python Very nice color blue and green keys TI calculators are well made and virtually last forever	I already have a calculator I already have Pythons Easier to type/view code on a computer Cannot use when wearing contacts (keys/screen too small) Does not have as many dedicated functions as my TI-30XA (DEG->RAD, DMS->DD, etc.) No QWERTY Will Python last forever?

Interactive Jupiter images at NOIRLab.

Tue 2021-05-11 16:47

NOIRLab put together a really cool interactive experience that lets you compare simultaneous Jupiter images at multiple wavelengths. The data were obtained at Hubble and Gemini North observatories.

CREDITS: I'm grateful to NOIRLab staff for producing the release, with special appreciation to Vanessa Thomas for patiently meticulous writing, Lars Christensen for the idea of doing an image comparison, and Mahdi Zamani for giving the Jupiter data his special touch of vitality and glamour. The Gemini data are from program GN-2016B-FT-18 (PI Wong) and the Hubble data are from program GO-14839 (PI de Pater). Observations and processing were described in Wong et al. (2020) and de Pater et al. (2019). This work was enabled by the location of the Gemini North telescope within the Maunakea Science Reserve, adjacent to the summit of Maunakea. I am grateful for the privilege of observing Ka'āwela (Jupiter) from a place that is unique in both its astronomical quality and its cultural significance.

Great conjuction 2020.

Sun 2020-12-06 19:45

I'm fascinated with the 2020 Great Conjunction, because (1) there is an entire word ("great conjunction") specifically reserved for when Jupiter and Saturn are in the same place in the sky, and (2) Hubble would be able to capture images of both of them in a single pointing. But this is just a dream, because the relative positions of the Earth, Jupiter, and Saturn means that the grand giants appear too close to the Sun for Hubble to target. Otherwise, a parallel exposure using HST's ACS and WFC3 cameras could have imaged both planets at the same time!

Friends have been asking me about this event, so here is some more info:

When will it happen? The planets will be closest to each other in the sky on December 21 at 18:21 UTC (09:21 PST, thank you timeanddate.com), although this could vary by a few minutes depending on your location on the Earth. It will be daytime for half of us (including those in California), but that's OK. Jupiter and Saturn will be astoundingly close together for a few days before and after 21 December too. The best time to view them is just after sunset. They will be following the Sun down.
But someone said it was at 13:30 UTC. The conjunction is indeed closer to 13:30 UTC (04:30 PST), but conjunction specifically means the planets are at the same east-west coordinate (right ascension) in the sky. Because their paths are at different angles, the closest approach (called the "appulse") will be a few hours later at 18:21 UTC, when Jupiter has passed slightly to the east of Saturn.
Do I need a telescope? The great conjunction can be enjoyed without a telescope, especially if you get in the habit of taking a peek at the planets every few days leading up to it. A nice diagram here shows how Jupiter and Saturn approach over time. At conjunction, they will be closer together than any of the bright stars in the Pleiades. So depending on your eyesight, you may still be able to tell that they are two separate points of light. With binoculars, you'll be able to see Saturn's unique shape (the rings), and possibly some of the major satellites. With a telescope, you can see details on the disk of Jupiter, and the gap between Saturn and its rings... perhaps in a single frame! I am very excited to see what spectacular images the amateur astronomers manage to produce.

CREDITS: Timing and distance information comes from JPL Horizons, where geocentric observer position was selected. The simulated sky image was generated by the JPL Solar System Simulator, and the instrument footprints themselves were taken from the WFC3 Instrument Handbook. Gordy Bjoraker generated the solar system perspective view using the open-source Cosmographia visualization tool.

Jupiter's jet speeds in 2016.

Thurs 2016-10-20 12:22

Joshua Tollefson and I have derived zonal winds from the 2016 OPAL observations of Jupiter. Josh is leading a paper on this, but we wanted to release the wind profile in advance of publication, in the hope that the profile will be useful for comparison with the Juno microwave and infrared observations coming soon, as well as the full range of earth-based support observations going on during the Juno campaign.

The OPAL maps are already available on the OPAL archive page:

We hope to update the wind profile using new observations near December 11, when Juno conducts its next scientific measurements of Jupiter's atmosphere.

Jupiter 2016 (April) zonal winds (141 kb text file)
Current reference (until Tollefson et al. 2017 is published): Wong et al. (2016) DPS
Methods used: Asay-Davis et al. (2011)

TMT protests: Balanced discussion by a biased scientist.

Wed 2015-04-21 23:59

I started working with the Thirty-Meter Telescope's (TMT's) science advisory groups in 2014, eleven years after plans for the observatory started forming. At my first TMT meeting, Project Manager Gary Sanders reported on "adversarial questions" at public hearings held by TMT, and the view that observatories on Mauna Kea are like pimples on the boundary between land and sky. One thing Sanders impressed me with was his deeply respectful tone when discussing difficulties he called "more complicated than adaptive optics."

Adaptive optics is a simple battle, with a single metric of success: it's astronomers vs. atmospheric turbulence, where the winner is determined by the value of the Strehl ratio. But on Mauna Kea now, there are a host of factors to take into account. The advance of human knowledge of the universe. The undisputed best weather and clarity, darkest skies, and driest air in the northern hemisphere. The educational and economic state of a people oppressed and colonized for over 100 years. The ancestral, spiritual link to the Earth. The ability of different groups of humans to reach mutual respectful agreements. Religious freedom. Biodiversity. Fragile ecosystems. A clean line between land and sky.

Some facts and promises

Some of the objections to TMT are factually incorrect. A calmly-worded opposition statement claimed that the "Natural habitat, the watershed, conservation laws, cultural relevance, the illegal occupation of Hawai'i and a vision for the future are all being ignored as construction teams prepare to move forward." Another objection holds that lucrative Mauna Kea observatories generate millions of dollars of revenue, which are not shared with their Hawai'ian hosts. Some of these are easy to discount:

A very rigorous environmental impact study was conducted, and the observatory is to be a zero-waste facility.
The pimple effect is reduced by a location down from the summit and to the northwest. Only 14% of the island of Hawai'i actually has a line of sight to the observatory. The 600-ft elevation drop (compared to the higher-seated domes) reduces the area that will be able to see TMT, at a dear price to astronomers (the lowest-elevation domes are often the first to close when fog rolls in). The picture above shows that even from Waimea, where TMT would be visible, its much larger dome is less obtrusive than existing domes, due to the lower elevation of TMT.
The TMT site will not disturb any pu'u (cinder cones of spiritual significance). This is in contrast to prior observatory construction, which flattened some pu'u, leading to increased opposition to observatories on the summit.
TMT will directly support a vision for the future by creating jobs, many of them skilled tech jobs, for Hawai'ians. Substantial annual funding is already giving educational support to train Hawai'ians in STEM fields.
Observatories do not "generate revenue." There are a few for-profit observatories, and selling observing time is also being contemplated to sustain aging facilities like Lick. But world-class research facilities like TMT are actually revenue suckers, draining money from governments and universities to conduct scientific research with no concrete monetary benefit whatsoever.

And the native Hawai'ian voice is diverse. Some in favor of TMT say that the ancestors would be proud of Hawai'i's role in astronomical progress, and that the TMT project contributes to island education, culture, and economy. A concise (compared to this) and eloquent petition in favor of TMT was written by 18-year old native Hawai'ian Mailani Neal.

R.E.S.P.E.C.T.

One common complaint is the lack of respect coming from astronomers. In 2006, Kealoha Pisciotta (one of the first native Hawai'ians to work as a Mauna Kea telescope technician) expressed frustration that astronomers "never once have said, 'We screwed up and we're sorry.' They never once said, 'Thank you for letting us use your sacred temple.'" And professional activist Walter Ritte said he was so disappointed with University of Hawai'i's community dialogue in response to recent protests, that his "goal now is not to stop the building of this observatory. The goal now is to get all of these observatories off this mountain. They have crossed the line and they have really angered the Hawai'ian community."

The issue of respect is highly emotionally charged. And honestly, astronomers should be held accountable for lack of respect. But on an institutional level, TMT's engagement with the native community, and its adherence to the spirit and letter of the construction approval process, speak to strong respect for Hawai'ian values. I learned much much more about Hawai'ian culture from reading TMT's own Use Permit Application than I did from following #TMTshutdown tweets.

On an individual level, planetary astronomers including Mike Brown and Imke de Pater have demonstrated great respect for Hawai'ian culture by honoring it within their work. Haumea (Pluto's cousin), and its two small moons Hi'iaka and Namaka, were given names of Hawai'ian deities, linked by intricate similarities between the Hawai'ian legends and the physical characteristics of the objects themselves. In 2002, years before Pisciotta complained of a lack of gratitude among astronomers, de Pater's acknowledgements in a journal article about the atmosphere of Jupiter's moon Io read "The authors extend special thanks to those of Hawai'ian ancestry on whose sacred mountain we are privileged to be guests. Without their generous hospitality, none of the observations presented would have been possible."

Self-determination of minority peoples

But the protests against TMT are being used to "highlight another cause: Hawai'ian sovereignty." This may not seem fair to TMT. But guess what else isn't fair? A century of colonialist domination of Hawai'i, from the overthrow of Queen Lili'uokalani to the "banning" of Hawai'ian language in schools.

The suppression of Hawai'ian culture left folks with a diminished ability to provide community input when the first telescopes were being built on Mauna Kea. Even though TMT is exercising much greater sensitivity and respect in its current process, old resentments are now being spoken in a stronger voice. The hashtag is mightier than the pen.

TMT is a partnership between US universities (including University of Hawai'i), China, India, Japan, and Canada. The world is watching this controversy. People in the USA have been quick to condemn Chinese practices ranging from the colonization and cultural suppression of Tibet, to forced displacement for large public works projects like the World Expo or the Three Gorges Dam. It is essential that we set a good example for our TMT partners by respecting Hawai'ian beliefs, protecting Hawai'ian lands, and listening to the broad range of Hawai'ian viewpoints both in favor of TMT and against it.

I would rather see the telescope built at an inferior site, rather than built without respect for native values as previous observatories were. But much has changed since observatories began popping up on Mauna Kea. No new observatories will ever be placed atop the summit or on/near sacred pu'u. TMT's construction/operations plan resulted from a process of respectful dialog, and this process also deserves respect.

Moon shadow, moon shadow.

Fri 2015-03-20 21:28

A lot of cool things have been going on lately with solar eclipses on Jupiter, or "shadow transits." Giovanni Cassini was the first to actually observe one of these events (upper left), back in the 1600s at the dawn of the telescopic era of astronomy. He used his observations to implement one of Galileo's ideas: to use the timing of mutual events (eclipses and transits) as a type of absolute clock that could work anywhere on the Earth, back before atomic clocks or quartz oscillators were available.

These events can be visually stunning, as the Hubble images of a rare triple-transit (lower left) show. Last month, I joined some Space Telescope Science Institute folks and Scott Lewis from knowthecosmos.com for a 1-hour chat about the spectacular Hubble imaging data (lower right). It was a good time, and Susana Deutua from the Institute showed off her Galileoscope, a replica of the telescope used by Galileo himself.

Just this week, right in the middle of the LPSC meeting, I participated in a super exciting remote-observing session at the IRTF telescope on Mauna Kea. The PI of the observing program, Gordy Bjoraker, came up with a brilliant way to use shadow transits. Our goal was to measure infrared spectra, made up of thermal emission from the deeper atmosphere. We're using the data to figure out just how deep Jupiter's water clouds lie. However, near Jupiter's equator, things get tricky — thick clouds there also reflect sunlight that is still weakly present at 5-μm wavelengths. Gordy wanted to get a spectrum of just the thermal emission, without that pesky reflected sunlight. Io to the rescue! Io's shadow conveniently blocked most of the sunlight from the clouds in a little spot (screenshot by Tilak Hewagama at upper right), allowing us to take a pure thermal spectrum within the shadow.

Analysis of these fresh data will take a while, but it's definitely worth the wait. We'll be sure to have results before the Juno spacecraft gets to Jupiter and conducts its highly complementary observations.

Giant storms on giant planets

Fri 2014-10-03 10:54

When Voyager passed by Uranus in 1986, none of this was going on. Of course, the "blue" image above is false color, applied to infrared images of Uranus from the Keck Observatory. These storms are a lot more dramatic in the infrared. But still, seven years after equinox in Uranus' 84-year annual cycle, storm activity seems to be picking up.

The storms themselves, at least visually, look similar to storms on Jupiter and Saturn, as seen in the infrared. These storms are rare on any of the giant planets, but there are a lot of questions about them. How much of the planets' internal heat do these superstorms carry? How often do they happen? Are they part of long term cycles?

This is what I love about studying the solar system. It never gets old. Things change and evolve over time.

LPSC Megablog.

Thu 2013-03-21 6:05pm in TX

Microblogging is really big at LPSC. I'm not a microblogger, or any kind of blogger really. I worry that as technology advances, and attention spans shrink, I am developing a mental disability. Short attention spans used to be characteristic of an attention deficit disorder. But now short attention spans are normal, and those who prefer to devote attention to things for longer amounts of time are the anomalous ones. So I think I have Attention Excess Disorder. Pharmaceutical companies, please develop some medicine for me so I can microblog.

I had lunch today with Max Mutchler from STScI (a collaborator on Planet Pipeline and Planet Investigators), and I was amazed to find out that he's a kidney donor just like me! I'm not shocked to meet a kidney donor. But to collaborate with one for more than three years, only to find this out halfway through lunch, was quite a shock. We talked about how we were affected by the situations that made our operations necessary, rather than the operations themselves.

I forgot to ask Max whether he was ever told, as I was recently by a friend, "You? You're the LAST person I would expect to be a kidney donor!"

On my quest for free stuff in the exhibitors section, I came across edible rocks courtesy of the CPSX booth (which they bought from a store nearby). Pictured are a black one and a yellow one. They look exactly like rocks, but they're chocolate! I'm looking around for Laurie Leshin, because she said during her talk that Curiosity finds 150-μm grains to be the "yummiest" dirt; but now, the rover is not the only one who eats rocks!

Using pine and bmail.

Sat 2013-02-09 18:02

I hate change! That's why I still use pine. My nephew saw my screen last night and was like "Wow, look at all those lines of code!" It was just pine. Nobody even knows what it is. But for the few that still use it, and who want to be able to use it with Berkeley's new bMail service, here's how to set it up.

Follow step 1 and 2 (only) here, to set bmail configuration options and to generate a google key that you need for login: http://kb.berkeley.edu/campus-shared-services/page.php?id=26754.

In pine, go to the setup screen (M-S-C keys). Find and set the following config lines:

     SMTP Server (for sending) = smtp.gmail.com/ssl/user=username@berkeley.edu
     Inbox Path = {imap.gmail.com/ssl/user=username@berkeley.edu}inbox

Now when you use pine, it will prompt you for your ugly-looking google key when you try to use email. This next step is optional, but it will allow pine to retain the key so you don't have to keep entering it:
- Create your pine-password storage file, if it doesn't already exist. At the command line, type touch ~/pine.pwd. The file name can be anything, but this is the name they used on the page that showed me how to do this. The file wil contain your google key, but encrypted.
- From now on, start pine with the right option to look for the password file. You can either type the option every time, or include an alias in your startup file. I only know how to do this for the csh/tcsh shells: cat alias 'pinemail pine -passfile ~/pine.pwd' > .cshrc. For other shells, you would probably need to change the syntax for the alias command, and/or store the command in another file (like profile.bash instead of .cshrc or something).
- Now start pine, with the -passfile option. When it asks for a password, enter the google key from step 1. Pine should then store it in the pine.pwd file, so you never have to ener it again.

Thanks Google! That was much easier than trying to get pine to work with Microsoft Exchange.

They don't make school lunch the way they used to.

Thu 2012-11-08 16:28

I had a great time this week, speaking to 311 students at South Pointe Middle School in Diamond Bar on Tuesday (thanks, Kellie Muragishi!), and 36 students in the Robotics Magnet Class at Audubon Middle School in Crenshaw yesterday (thanks, Eric Yu!).

JPL's Mars office set me up with a rover model and a full size model rover wheel, and Scott gave me some NASA "meatball" stickers to hand out. These were great bribes to encourage the students to ask questions at the end. Some highlights:

I got more questions about my inspiration and enjoyment of work, than about how much money I make. But they still did ask.
When I asked what social/environmental issue relates to CO₂ in the atmosphere, none of the students in Diamond Bar guessed that I was thinking climate change. Several of the Crenshaw students almost immediately knew what I was fishing for.
School lunches have changed since I was little... similar to how airplane food changed. They used to be little cooked meals from the school kitchen, but now the lunches are pre-packaged corporate food. I had Subway sandwich at South Pointe, and another option was a pita-pack encased in a black plastic tub with a plastic sheet that you have to peel back to get to the food. Maybe I didn't get in the right line, because another guy in the Faculty Lounge was eating a school lunch in a small white Chinese takeout box.

Flash news.

Tue 2012-09-11 12:34

What an exciting night. Or day. Or sol?

I slept in yesterday, missing some key emails, and showed up to work "early" for my shift doing MSL operations work (at 8pm). That's when I found out there was another Jupiter fireball. This one was discovered by Dan Petersen in Wisconsin by visual observation, and confirmed when George Hall went back and found the flash in his archived video.

Being simultaneously pulled to work on Mars and Jupiter made me almost believe in astrology. I definitely felt that the planets were controlling my life.

About the image: My lightcurve has a large uncertainty, but is sufficient to predict that this event is too small to create a visible impact scar. George Hall was kind enough to share his video data for this analysis. The inset image consists of 22 frames of George's data, stacked by Ricardo Hueso and treated with a mild high-pass filter. Light curve data points are based on radial brightness curves, extrapolated to compensated for saturated pixels in the original data.

More detailed reports include:

Time Lapse Saturn/Jupiter Video: "Outer Space."

Wed 2012-05-02 12:09

I just found out about this awesome video by Sander van den Berg, using Voyager and Cassini imaging data. If you're like me, you've seen some of the videos in this compilation, but this is a really breathtaking new way to absorb them. A lot of physics, some understood and some not, is captured in this 1:52 piece.

Space Senator.

Thu 2012-04-12 14:01

I just went to browse MAST, formerly the Multimission Archive at STScI, and found out that it's been renamed. It's still MAST, but now it stands for the Mikulski Archive for Space Telescopes.

Senator Barbara Mikulski was honored for becoming the longest-serving woman in U.S. Congressional history, and also for being a great defender of space exploration and research. There are nice writeups about MAST and Sen. Mikulski on the about MAST page and a Hubble press release. Although some NASA advocates focus their support on the manned space program with its associated defense contractor expenditures, Senator Mikulski's record shows support for the kind of stuff I do: science. I'm proud that they renamed the archive after her.

Space Ronin.

Tue 2012-02-28 12:20

My career is not not going quite the way I thought it would, back when I was 18. Shouldn't I have a faculty job by now? Or a civil servant position at NASA?

These days, many people adopt different paths. We branch out, or we work at scientist farms, where top-quality researchers can sustain themselves on grants. So I'm starting a new (part-time) Visiting Scientist gig at University of Michigan, following on an awesome Visiting Scientist stint at Space Telescope in 2009-2010. At Michigan I'll be working with the SAM instrument on the Curiosity rover.

Although a part-time visiting scientist arrangement is odd, and inconvenient... I don't think it's extremely unusual these days. I'm a Space Ronin; I have no tenure and I work here and there. I'm well regarded internationally in my field, but just without the job to match. I console myself in the quote usually found on the whiteboard behind the bar at Tommy's: "IF YOU LIVE IN S.F. PLEASE REMEMBER HOW LUCKY YOU ARE."

NASA's new map of ocean salt concentration.

Thu 2011-09-22 14:33

This is the first map showing the salt concentration at the ocean's surface that was taken by NASA's Aquarius instrument, flying aboard Argentina's Earth observation satellite SAC-D (Satélite de Aplicaciones Científicas).

What's cool about this map? You can see how salt and fresh water interact in the ocean. Purplish regions, especially near continental coastlines, show relatively fresh water delivered by river systems. NASA calls the extensive fresh outflow from the Amazon delta "surprisingly large."

Other features—like the blue stripe near the equator and orange blobs in the tropics/subtropics north and south of the equator—are well understood effects caused by strong evaporation at the tropics/subtropics and heavy rainfall at the equator.

As Aquarius makes more and more of these maps, it will be fascinating to see how these patterns change with season, or with climatic events such as El Niño.

Great launch for Juno mission to Jupiter.

Fri 2011-08-05 14:16

NASA's offering a pretty launch video of the Juno spacecraft being carried to space aboard an Atlas 5. My former graduate advisor was there at the launch, so I'll have to ask him what his impression was. Solar-powered Juno will reach Jupiter in 5 years with only one Earth flyby gravitational assist, slightly faster than nuclear-powered Galileo's 6-year cruise with a Venus flyby and two Earth flybys. Juno is a much smaller mission, with specific goals, and it only will cost about 80% of the $1.4B Galileo missions total pricetag. Juno's cost is about half the cost of a Space Shuttle, and about 2x the cost of a Space Shuttle launch.

From my perspective, the most exciting Juno observations will be it's super-deep probing radio-wave measurements of gas opacity in the deep polar atmosphere. The mission hopes to capture the holy grail of Jupiter compositional studies: a measure of the deep water abundance. Another exciting contribution will be the hi-definition measurements of Jupiter's gravitational (and magnetic) fields. The gravity data will help us define the structure of Jupiter's core regions, as well as its deep wind flows and currents.

NASA gives a great summary of why the name Juno was picked:

In Greek and Roman mythology, Jupiter drew a veil of clouds around himself to hide his mischief. It was Jupiter's wife, the goddess Juno, who was able to peer through the clouds and reveal Jupiter's true nature. The Juno spacecraft will also look beneath the clouds to see what the planet is up to, not seeking signs of misbehavior, but helping us to understand the planet's structure and history.

Speaking of names, dictionary.com recently opened a 606-comment debate (as of now) about what Pluto's new moon should be called. The moon is really dinky, but I still think it's about time we got something named after Cerberus, or maybe Kerberos since Asteroid 1865 is already called Cerberus.

Pluto's new moon.

Wed 2011-07-20 16:18

In another bid to render textbook entries about it obsolete, Pluto has revealed its fourth, and smallest, satellite. This is yet another outstanding discovery by Mark Showalter, who also recently found that small bodies impacting Jupiter and Saturn can create long-lasting ripples in the planets' ring systems.

Pluto's new moon "P4" was discovered using the WFC3/UVIS detector, which I helped to calibrate and support when I was in Baltimore.

I just uploaded the image below, a calibration test frame for CCD Chip 2 of WFC3—the very same chip that discovered P4—to this great but not very active site called my art in science. If you have any pretty scientific images of your own, my art in science is a great place to share it.

New office, new astro-blog.

Wed 2011-07-13 18:09 PDT

Along with most of the Astronomy Department, I've moved to the Hearst Field Annex (HFA). Here we await the demolition of Campbell Hall, and the building of New Campbell Hall.

Cubicle life is lovely. I'm located near the blue dot in the map above, everything smells like new carpet, new toys are in use (an IRC channel and a ping pong table), and we have water coolers.