@AkaSci@fosstodon.org
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AkaSci

@AkaSci@fosstodon.org

SatCom Scientist
Writing occasionally about space missions, astronomy, planetary science, satellites and science in general.
He/Him
#science #space #technology #astronomy #satellites #Democracy

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johncarlosbaez, (edited ) to random
@johncarlosbaez@mathstodon.xyz avatar

If you could watch an individual water molecule, about once in 10 hours you'd see it do this!

As it bounces around, every so often it hits another water molecule hard enough enough for one to steal a hydrogen nucleus - that is, a proton - from the other!

The water molecule with the missing proton is called a hydroxide ion, OH⁻. The one with an extra proton is called a hydronium ion, H₃O⁺.

This process is called the 'autoionization' of water. Thanks to this, roughly one in ten million molecules in a glass of water are actually OH⁻ or H₃O⁺, not the H₂O you expect.

And this explains why protons can move through water much more easily than larger ions can. Let's watch how it works.

(1/n)

w7voa, to random
@w7voa@journa.host avatar

Our launch event for ‘Behind the White House Curtain’ is this evening at the National Press Club. Please join us if you’re in Washington. https://www.press.org/events/npc-headliners-book-event-steve-herman-behind-white-house-curtain

megschwamb, to Astro
@megschwamb@mastodon.online avatar

Hubble moves to single gryo mode. This moves ensures the space telescope can keep on observing well reserving/saving one of the good functioning gyros for the future. https://science.nasa.gov/missions/hubble/nasa-to-change-how-it-points-hubble-space-telescope/

megschwamb,
@megschwamb@mastodon.online avatar

A quick search found this article. Seems like a nice summary of what is capable and not capable in one gyro mode. https://www.stsci.edu/files/live/sites/www/files/home/hst/about/space-telescope-users-committee/presentations-and-documentation/_documents/2019_may/GYRO_Science_Considerations.pdf

TMEubanks, to random
@TMEubanks@astrodon.social avatar

The International Astronomical Union and WNYC’s award-winning science podcast, Radiolab, invite people worldwide to take the unique opportunity to suggest a name for one of Earth's quasi-moons. Submissions are open until 30 September and the winning name will receive official recognition by the IAU.
https://iau.org/news/pressreleases/detail/iau2406/

inautilo, to design
@inautilo@mastodon.social avatar


The power of beauty in communicating complex ideas · What we often overlook in visualizations and infographics https://ilo.im/15z2oh

pbump, to random
@pbump@journa.host avatar

Expansive new data from YouGov shows where Americans get their news — and how much they trust it. https://www.washingtonpost.com/politics/2024/05/31/trust-news-sources/

startswithabang, to random
@startswithabang@astrodon.social avatar

Is the “Methuselah star” really older than the Universe?

The Universe is 13.8 billion years old.

The Methuselah star, on the other hand, is estimated to be 14.5 billion years old.

Here's why that's no problem for astrophysics.

https://bigthink.com/starts-with-a-bang/methuselah-star-older-than-universe/

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

Fresh volcanic eruptions north of Grindavîk, Iceland.

  • Started at 1 pm local (UTC)
  • Fissure location is similar to Dec 19 and Mar 16 eruptions
  • Strong M4.1 earthquake in the area around 11 am
  • Magma likely in contact with groundwater causing explosions and dark plumes of smoke
  • Grindavík, the Blue Lagoon and the power plant in Svartsengi evacuated
  • This eruption is the most powerful in the current system so far.

News: https://www.ruv.is/english/2024-05-29-eruption-on-reykjanes-peninsula-413853
https://www.facebook.com/Almannavarnir
#Iceland
1/n

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

29 May 1953 - Edmund Hillary, an explore and mountaineer from New Zealand, and Tenzing Norgay, the Nepalese Sherpa mountaineer, became the first people to stand on the summit of Mt. Everest, the world’s highest peak.

The pic of Tenzing below was taken by Edmund Hillary using the Kodak Retina 118 camera. The camera is displayed at the Otago Museum in Dunedin, New Zealand.
https://www.smithsonianmag.com/smithsonian-institution/sixty-years-ago-edmund-hillary-reached-the-top-of-the-world-hear-him-describe-it-76861267/
https://retrofilmcamera.com/kodak-retina/
#Everest
1/n

KeithDJohnson, to climate
@KeithDJohnson@sfba.social avatar

A useful & startling chart: "A look back at half a billion years of earth’s #climate history. Within about 25 years we will be entering a temperature realm not seen since the #Pliocene 3 million years ago."
[Article is one year old.]
https://medium.com/@samyoureyes/the-busy-workers-handbook-to-the-apocalypse-7790666afde7

drewharwell, to random

"The justice told Fox News that his wife hoisted the flag in response to Ms. Baden’s vulgar insult. A text message and the police call — corroborated by Fairfax County authorities — indicate, however, that the name-calling took place on Feb. 15, weeks after the inverted flag was taken down" https://www.nytimes.com/2024/05/28/us/justice-alito-neighbors-stop-steal-flag.html

AkaSci, to random
@AkaSci@fosstodon.org avatar

Happy Birthday to Frank Drake (May 28, 1930 – Sept 2, 2022), astrophysicist, astrobiologist and creator of the Drake equation, which is used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy.

The equation was formulated in 1961 as a way to stimulate discussion at the 1st scientific meeting on the search for extraterrestrial intelligence (SETI) at the National Radio Astronomy Observatory site at Green Bank, WV.

https://en.wikipedia.org/wiki/Frank_Drake
1/n

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

Searing heat in India today.
Max. recorded temp: 49.8°C
Many central regions of the country with above 40°C temperatures.
May tends to be the hottest month in India.
Source: India Meteorological Department

1/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

The widely reported max temperature in Delhi yesterday of 52.9°C is likely inaccurate and may be caused by a sensor error.

Here is the statement from the India Meteorological Department -

"The maximum temperature over Delhi NCR varied from 45.2° to 49.1°C in different parts of city, Mungeshpur reported 52.9°C as an outlier compared to other stations. It could be due to error in the sensor or the local factor. IMD is examining the data and sensors."

https://mausam.imd.gov.in/Forecast/marquee_data/Press%20Release_Delhi%20Temp.%20dated%20%2029-05-2024.pdf
#India #HeatWave
7/n

KimPerales, (edited ) to climate
@KimPerales@toad.social avatar

FL is a toxic place to live bc of #DeathSantis & GOP lawmakers. They won't admit it's CC or mitigate...

The backyard would flood & the toilet would gurgle & the smell of sewage hung thick in the air -she worried about what pathogens might lurk in the tainted waters, what it might cost to fix the persistent problems & whether the ever-present anxiety would ever subside. Residents in neighborhoods around hers have similar tales-.

#GOPCorruption #Pollution #ClimateChange
https://www.washingtonpost.com/climate-environment/interactive/2024/septic-tanks-rising-waters-environment-health/

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

The largest camera ever built for astrophysics arrived this week at the Rubin Observatory at Cerro Pachón in Chile.

The LSST camera, built by the SLAC National Accelerator Laboratory in Menlo Park, CA, is the final major component of the Rubin Observatory's Simonyi Survey Telescope to arrive at the summit.

Development of the observatory has been funded by the NSF and the DOE.

First light is expected in Dec 2024.

https://www.youtube.com/shorts/jB1s_YEcJi8
https://rubinobservatory.org/news/camera-arrives-chile
1/n

AkaSci,
@AkaSci@fosstodon.org avatar

The Rubin Observatory Simonyi Survey Telescope consists of 3 aspheric mirrors: an 8.4-m primary mirror M1, a 3.5-m convex secondary mirror M2, and a 5.0-m tertiary mirror M3.

The primary and tertiary mirrors are fabricated from a single piece of glass.
The secondary mirror (M2) is the largest convex mirror ever made.
Field of view = 3.5°.
The 3.2-gigapixel camera hangs below the secondary mirror.
https://www.lsst.org/about/tel-site/optical_design
#Rubin #astronomy
2/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

The focal plane of the Vera C. Rubin telescope consists of 189 charge-coupled device (CCD) sensors, arranged in a total of 21 3-by-3 square arrays. The system is cooled to about -100 °C to minimize noise.

The 3.5° field of view of the 64 cm wide array is 40 times the area of the full moon in the sky.

Camera Data Rates: ~3.2 GBytes/sec peak raw data
1 pixel = 16 bits (raw)
Pixels: 3.2 billion!
Detector read-out time: 2 sec

https://rubin.canto.com/v/gallery/album/HDSNU?display=curatedView&viewIndex=2&column=image&id=o46f0msu2d6733e7v1r2opt66t
https://www6.slac.stanford.edu/lsst
#Rubin
4/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

The Rubin Legacy Survey of Space and Time LSST Camera is the largest camera ever constructed for astronomy. It is a large-aperture, wide-field optical camera, capable of viewing light from the near ultraviolet to near infrared wavelengths.

Length: 3.73 m
Height: 1.65 m
Weight: 2,800 kg
Pixels: 3.2 billion
Wavelength: 0.32–1.06 μm
Filters: 6 (u-g-r-i-z-y)
Field of view = 3.5° (moon = 0.5°)
Operating temperature: -100°C

https://www6.slac.stanford.edu/lsst
https://www.lsst.org/about/camera/features
#Rubin #astronomy
3/n

AkaSci,
@AkaSci@fosstodon.org avatar

The goal of the Rubin Observatory is to conduct the 10-year Legacy Survey of Space and Time (LSST). Its objectives include -
• Probing dark energy and dark matter
• Taking an inventory of the solar system
• Exploring the transient optical sky
• Mapping the Milky Way

The LSST will image the entire visible sky every 3-4 nights, allowing it to detect objects that change in brightness or position and to discover billions of new stars and galaxies.

https://www.lsst.org/about
7/n

iangriffin, to random
@iangriffin@mastodon.nz avatar

Just for fun. I added together all of the images I took of Comet Pons Brooks a few weeks ago. The session was just after astronomical twilight and every single frame I took (68) had at least one satellite trail. To really piss me off, a whole train of freshly launched Starlink satellites joined the "party". This, friends, is the price we pay for "progress". #notostarlink #savethesky

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

An iceberg named A-83, 380 sq km in size, broke off the Brunt Ice Shelf in Antarctica on May 20.

"This calving event results from a prolonged weakening of the ice at the McDonald Ice Rumples and progressive eastward extension of the so-called ‘Halloween Crack’ into the ice shelf."

In 2021, the Brunt Ice Shelf produced an iceberg called A-74 followed by an even bigger berg, named A-81, in 2023.

https://www.esa.int/ESA_Multimedia/Images/2024/05/Iceberg_A-83_breaks_free
https://earthobservatory.nasa.gov/images/152848/antarctic-ice-shelf-spawns-iceberg-a-83

1/n

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

The NASA Europa Clipper spacecraft is getting ready to be shipped to KSC in FL. The spacecraft was moved in the clean room at JPL next to the container which will be used for transport to KSC.

At KSC, solar panels will be attached before installation in the SpaceX Falcon Heavy rocket for launch around Oct 10, 2024. It will be inserted into orbit around Jupiter on April 11, 2030, from where it will make close passes of Europa over 4 years.

Webcam of clean room at https://europa.nasa.gov/spacecraft/assembly/
1/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

The Europa Clipper spacecraft arrived at the Kennedy Space Center in FL yesterday, May 23, aboard a USAF C-17 Globemaster III transport aircraft.

The spacecraft, safely ensconced inside its special shipping container, was then trucked to the Payload Hazardous Servicing Facility in KSC.

In the next month or so, solar panels will be attached. The assembled spacecraft will then be installed in a SpaceX Falcon Heavy rocket for launch on Oct 10, 2024.

https://www.jpl.nasa.gov/news/nasas-europa-clipper-makes-cross-country-flight-to-florida

5/n

AkaSci, to random
@AkaSci@fosstodon.org avatar

Happy Birthday to the Hubble Space Telescope, launched OTD in 1990, with Space Shuttle Discovery during the STS-31 mission.

34 years and 5 servicing missions later, Hubble is still going strong, unfolding the mysteries of the Universe from its perch 540 km above earth.

https://www.flickr.com/photos/nasahubble/albums/72157670398668526/
https://hubblesite.org/home
1/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

As we suspected, the NASA Hubble team has decided to operate Hubble henceforth in single gyro mode.

There are some limitations in this mode - Hubble will need more time to slew and lock onto a science target and won't have as much flexibility as to where it can observe at any given time.

The other healthy gyro will be kept as a spare. Hubble now has 4 failed gyros.

The team expects to resume science operations again by mid-June.

https://science.nasa.gov/missions/hubble/nasa-to-change-how-it-points-hubble-space-telescope/
https://science.nasa.gov/mission/hubble/observatory/design/hubble-one-gyro-mode/

8/n

AkaSci, (edited )
@AkaSci@fosstodon.org avatar

Note that gyros are used to accurately determine Hubble's pointing direction. Telescope movement is done using reaction wheels and magnetic torquers.

In one-gyro mode, Hubble supplements info from the gyro with info from its magnetometers, sun sensors, star trackers and fine guidance sensors + some nifty software processing. It's a slower process but once Hubble is on target, pointing accuracy is comparable to that of 3-gyro mode.

https://science.nasa.gov/mission/hubble/observatory/design/hubble-one-gyro-mode/
https://fosstodon.org/@AkaSci/111502315407828522

9/n

AkaSci, (edited ) to random
@AkaSci@fosstodon.org avatar

It's alive :mastodance:

The JAXA SLIM lander, lying in its awkward stance on the lunar surface, responded last night to a command sent by JAXA. Against all hope, it appears that it survived the cold lunar night.

The batteries were expected to get charged around this time, shortly after lunar midday, since the solar panels are facing southwest instead of up.

Apparently, the temperature of the comm equipment was too high, so comms was quickly terminated. Stay tuned!

1/n

AkaSci,
@AkaSci@fosstodon.org avatar

The JAXA SLIM lunar lander was expected to wake up again around May 24, hopefully having survived a 4th brutal lunar night. After all, against all odds, it had survived the first 3 nights.

But it has not responded in two attempts made so far. Perhaps, its electronics finally succumbed to the lunar elements? The #SLIM team will try again tomorrow.

Note that the solar panels get sunlight well after lunar noon due to their unfortunate orientation with the lander in the upside down position.
🤞
6/n

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