In the Sky This Week – December 3, 2019
At last night's meeting of the Warren Astronomical Society, the topic of the Starlink satellite constellation came up during the "In the News" segment, and a groan of dismay could be heard from the entire audience. If you are unfamiliar with Starlink, it is a constellation of potentially tens of thousands of communication satellites created by SpaceX with the goal of providing global high-speed internet - that concept sounds great!
Starlink satellites during a meteor shower on Nov. 22. pic.twitter.com/wJVk1qu49E
— Patrick Treuthardt, Ph.D. (@PTreuthardt) November 25, 2019
The first time I became aware of Starlink was after the 2nd satellite deployment mission of May of 2019, when 60 satellites were put into a 53° Earth orbit. Almost immediately satellite sightings started pouring in from around the world. Videos show a long trail of lights traversing the sky, virtually painting the orbits of the satellites in your mind's eye, and literally painting them in the cameras of astronomers and astrophotographers - who have started complaining loudly!
The NGC 5353/4 galaxy group is obscured by more than 25 Starlink satellite trails in this May 2019 image, taken from Lowell Observatory in Flagstaff, Arizona. Credit: Victoria Girgis/Lowell Observatory
The International Astronomical Union posted this statement on June 3, 2019:
Over the past decades, considerable effort has gone into designing, building, and deploying satellites for many important purposes. Recently networks, known as satellite constellations, have been deployed and are planned in ever greater numbers in mainly low-Earth orbits for a variety of purposes, including providing communication services to underserved or remote areas. Until this year, the number of such satellites was below 200, but that number is now increasing rapidly, with plans to deploy potentially tens of thousands of them. In that event, satellite constellations will soon outnumber all previously launched satellites.
The International Astronomical Union (IAU) is concerned about these satellite constellations. The organisation, in general, embraces the principle of a dark and radio-quiet sky as not only essential to advancing our understanding of the Universe of which we are a part, but also as a resource for all humanity and for the protection of nocturnal wildlife. We do not yet understand the impact of thousands of these visible satellites scattered across the night sky and despite their good intentions, these satellite constellations may threaten both.
The scientific concerns are twofold. Firstly, the surfaces of these satellites are often made of highly reflective metal, and reflections from the Sun in the hours after sunset and before sunrise make them appear as slow-moving dots in the night sky. Although most of these reflections may be so faint that they are hard to pick out with the naked eye, they can be detrimental to the sensitive capabilities of large ground-based astronomical telescopes, including the extreme wide-angle survey telescopes currently under construction. Secondly, despite notable efforts to avoid interfering with radio astronomy frequencies, aggregate radio signals emitted from the satellite constellations can still threaten astronomical observations at radio wavelengths. Recent advances in radio astronomy, such as producing the first image of a black hole or understanding more about the formation of planetary systems, were only possible through concerted efforts in safeguarding the radio sky from interference.
The IAU is a science and technology organisation, stimulating and safeguarding advances in those areas. Although significant effort has been put into mitigating the problems with the different satellite constellations, we strongly recommend that all stakeholders in this new and largely unregulated frontier of space utilisation work collaboratively to their mutual advantage. Satellite constellations can pose a significant or debilitating threat to important existing and future astronomical infrastructures, and we urge their designers and deployers as well as policy-makers to work with the astronomical community in a concerted effort to analyse and understand the impact of satellite constellations. We also urge appropriate agencies to devise a regulatory framework to mitigate or eliminate the detrimental impacts on scientific exploration as soon as practical.
The IAU’s Commission B7 Protection of Existing and Potential Observatory Sites welcomes the opportunity to work proactively with everyone involved in these efforts. - IAU
Elon Musk initially dismissed astronomer's complaints, but has since agreed to take steps to reduce the albedo of the satellites; I've seen comments by supporters (or quite possibly internet trolls) accusing detractors of being Luddites - these Luddites would include astronomers who use high-tech multi-million dollar equipment... While I was researching the Starlink launch date for this post, I was surprised at the rather lengthy history section of the Wikipedia entry, and embarrassed at my near total lack of knowledge of that history. This story certainly has my attention now; I'm certain this story will be on-going and developing over the next several years.
The Moon appears in the sky at 3:00 PM for several days this week - about the time schools get out. If it's clear, I want to bring my 'scope to my after-school club and have the students see it.
The Moon appears above the east-southeastern horizon at 3:00 PM from Dec. 3-6th. Credit: Stellarium / Bob Trembley
Mercury, Mars and the star Spica align above the southeastern horizon before sunrise this week.
Mercury, Mars and the star Spica align above the southeastern horizon before dawn this week. Credit: Stellarium / Bob Trembley
Several planets appear above the southwestern horizon shortly after sunset this week. Jupiter sets soon after sunset, leaving Saturn and Venus above the southwestern horizon - great observing targets!
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- Jupiter is very low, Venus and Saturn are higher above the southwestern horizon after sunset this week. Credit: Stellarium / Bob Trembley
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- Shortly after sunset, Venus and Saturn appear above the southwestern horizon this week. Credit: Stellarium / Bob Trembley
The Moon appears high above the south-southeastern horizon after sunset for several days this week - this is an ideal time to observe the Moon with binoculars or a telescope.
The Moon high above the south-southeastern horizon after sunset for several days this week. Credit: Stellarium / Bob Trembley
The Andromeda galaxy appears almost directly overhead around 8:30 PM this week - as do the constellations Andromeda and Pegasus.
The constellations Pegasus and Andromeda appear directly overhead around 8:30 PM this week. Credit: Stellarium / Bob Trembley
Starlink Satellites
Let me know if you have an observing session this week where you do NOT see a Starlink satellite.
The Moon is a waxing crescent, visible toward the southwest in early evening - the Moon is a great observing target this week!
The Moon will be at first quarter on Dec. 4th, it will be visible high in the southern sky in early evening.
After Dec. 4th, the Moon will be a waxing gibbous, visible to the southeast in early evening, up for most of the night.
Moon News
These fractures in Komarov crater were made by magma – yes, you read that right – magma. Molten material bubbled up below the surface, pushing the Moon’s crust up and fracturing it in the process. This image shows an area just over 9 miles (15 km) wide. https://t.co/SCN9z6S1C3 pic.twitter.com/jzuVbLU92B
— NASA Moon (@NASAMoon) December 3, 2019
The Sun has been spotless for 20 days; large coronal holes appear at both poles - the southern hole has gotten very large .
The Sun seen in 193 angstroms (extreme ultraviolet) Dec. 2, 2019:
Several prominences on the Sun's l today! I'm going to have to crack out my solar telescope when I finish this post!
The Sun seen in 304 angstroms (extreme ultraviolet) Dec. 2, 2019:
Videos courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
The solar wind speed is 297.0 km/sec (↓), with a density of 4.5 protons/cm3 (↑) at 1550 UT.
Facebook: SolarActivity
Animated LASCO C2 Coronograph showing the solar corona above the Sun's limb (the white circle). Credit: NASA/JPL-Caltech
You can create your own time-lapse movies of the Sun here: AIA/HMI Browse Data.
You can browse all the SDO images of the Sun from 2010 to the present here: Browse SDO archive.
Sun News
On Dec. 4, scientists are sharing new discoveries about the Sun from #ParkerSolarProbe — and we’ll discuss with experts during #NASAScience Live!
🗓️ Dec. 4
🕒 3pm ET / 12pm PT
🔗 https://t.co/Uqi7MpLDD7
❓ #askNASA pic.twitter.com/sx31rGLa11— NASA Sun & Space (@NASASun) December 3, 2019
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2017 AP4 |
2019-Dec-03
|
8.5 LD
|
7.5
|
15
|
| 2019 WW |
2019-Dec-05
|
8.6 LD
|
9.8
|
43
|
| 2019 WB5 |
2019-Dec-06
|
18.7 LD
|
22
|
48
|
| 2019 WR3 |
2019-Dec-06
|
14.2 LD
|
7.5
|
98
|
| 2019 WJ6 |
2019-Dec-07
|
7.5 LD
|
21.1
|
47
|
| 2018 XW2 |
2019-Dec-07
|
17.4 LD
|
13
|
28
|
| 2019 VH5 |
2019-Dec-08
|
18 LD
|
9.8
|
73
|
| 2019 XB |
2019-Dec-09
|
17.4 LD
|
7.9
|
67
|
| 2019 WT3 |
2019-Dec-09
|
9.8 LD
|
11
|
41
|
| 2019 WO2 |
2019-Dec-09
|
4.8 LD
|
7.6
|
34
|
| 2019 XF |
2019-Dec-18
|
9.5 LD
|
24.4
|
78
|
| 216258 |
2019-Dec-20
|
15.3 LD
|
11.8
|
324
|
| 2013 XY20 |
2019-Dec-21
|
18.3 LD
|
1.9
|
28
|
| 2017 XQ60 |
2019-Dec-22
|
11 LD
|
15.6
|
47
|
| 310442 |
2019-Dec-26
|
19 LD
|
12.3
|
372
|
| 2019 WR4 |
2019-Dec-31
|
11.7 LD
|
4.3
|
21
|
| 2019 AE3 |
2020-Jan-02
|
4.9 LD
|
8.2
|
13
|
| 2019 UO |
2020-Jan-10
|
11.8 LD
|
9.4
|
361
|
| 2019 WC5 |
2020-Jan-11
|
6.4 LD
|
13
|
112
|
| 2011 EP51 |
2020-Jan-15
|
19.6 LD
|
7.1
|
32
|
| 2017 RZ15 |
2020-Jan-15
|
12.1 LD
|
7.4
|
14
|
| 2009 BH2 |
2020-Jan-18
|
14.6 LD
|
17.9
|
118
|
| 2013 DU |
2020-Jan-20
|
15.3 LD
|
6.4
|
59
|
| 2019 TF2 |
2020-Jan-23
|
16.2 LD
|
1.6
|
18
|
| 2018 BM5 |
2020-Jan-23
|
13.1 LD
|
8.6
|
12
|
| 2018 AL12 |
2020-Jan-30
|
18.2 LD
|
17.7
|
39
|
Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. Red highlighted entries are asteroids that either pass very close, or very large with high relative velocities to the Earth. Table from SpaceWeather.com
Potentially hazardous asteroids: 2018 (last updated Oct. 1, 2019)
Minor Planets discovered: 840,470 (+178)
Asteroid News: Hera Mission to Deflect an Asteroid Funded!
So proud! The #HeraMission was just approved by @esa during #Space19plus. Here is our official statement! Representing 1,600 scientists includibg Lord Martin Rees and @DrBrianMayhttps://t.co/stCiOINFCd pic.twitter.com/W8tOnvDeMP
— supportHera (@SupportHera) November 28, 2019
More on the Hera Mission:
Go for Didymoon! ESA's #asteroid #HeraMission for #PlanetaryDefense has been approved by Europe's space ministers at #Space19plus. The spacecraft will be Europe's contribution to the international #AIDA4Asteroids endeavour, teamed with @NASA's DART mission https://t.co/vEcmuPbfQw pic.twitter.com/PBBBurDRM1
— ESA Technology (@ESA_Tech) November 29, 2019
#HeraMission will be an extremely agile, 'self-driving' spacecraft to navigate around the double #DidymosAsteroid system, with a 780 m body orbited by a 160 m moon - seen here by #SagradaFamília in #Barcelona. It will carry 2 tiny #CubeSats to go closer https://t.co/vEcmuPbfQw pic.twitter.com/P3xZ6oZzud
— ESA Technology (@ESA_Tech) November 29, 2019
On Dec. 3, 2019, the NASA All Sky Fireball Network reported 50 fireballs.
(47 sporadics, 2 Nov. omega Orionids, 1 Quadrantids)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). From: Spaceweather.com
Interstellar comet 2I/Borisov might break apart as it goes around the Sun - https://t.co/XIn47xQxTn pic.twitter.com/PkNq8cHNdg
— Fraser Cain (@fcain) December 3, 2019
Position of the planets and a couple spacecraft in the inner solar system:
Position of the planets and some spacecraft in the inner solar system, Dec. 3, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets and a couple bodies in the middle solar system:
Position of the planets in the middle solar system, Dec. 3, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the outer solar system, transneptunian object (TNO) and possible dwarf planet 420356 Praamzius is highlighted in red:
Position of the planets in the outer solar system, Dec. 3, 2019, with the orbit of transneptunian object 2012 BX85 / (420356) Praamzius highlighted. Credit: SpaceEngine / Bob Trembley
420356 Praamzius, provisional designation 2012 BX85, is a trans-Neptunian object from the classical Kuiper belt, located in the outermost region of the Solar System, approximately 190–320 kilometers (120–200 miles) in diameter. It was discovered on 23 January 2012, by astronomers Kazimieras Černis and Richard Boyle with the Vatican's VATT at Mount Graham Observatory in Arizona, United States. The cold classical Kuiper belt object is a weak dwarf planet candidate and possibly very red in color. It was named after the chief god Praamžius from Lithuanian mythology. - Wikipedia
Artist conception of transneptunian object 2012 BX85 / (420356) Praamzius. Credit: SpaceEngine / Bob Trembley.
NASA's Interactive Real-Time Web-based Orrery:
Solar System News
Space Debris orbiting Earth
Credit: Technical University Braunschweig pic.twitter.com/UJSYe7oSR8
— Universal-Sci (@universal_sci) December 2, 2019
Another resource for space junk is http://stuffin.spaceli
OSIRIS-REx Asteroid Sample Return Mission
Wowza. Today marks one full year at Bennu 🎉
Celebrating everything that’s happened so far! #ToBennuAndBack pic.twitter.com/REekmfkjGG
— NASA's OSIRIS-REx (@OSIRISREx) December 3, 2019
International Space Station
The Exp 61 crew is focusing on U.S. and Russian space shipments after completing a spacewalk on Monday. Read more... https://t.co/JkBWZSseHX pic.twitter.com/zt7JreFOKH
— Intl. Space Station (@Space_Station) December 3, 2019
Juno Mission at Jupiter
Today, our @NASAJuno spacecraft orbits Jupiter, studying its magnetic field, atmosphere and deep interior. Image processed by Gerald Eichstädt.https://t.co/MrABgEFES8 pic.twitter.com/SFYhee52No
— NASA Solar System (@NASASolarSystem) December 3, 2019
NASA Climate
A vast animal migration – the largest on the planet and a critical part of Earth’s climate system – has been observed globally for the first time, thanks to an unexpected use of a space-based laser: https://t.co/8HtvKD4vTZ pic.twitter.com/NhNN1lfoh0
— NASA Climate (@NASAClimate) December 3, 2019
Data from the NASA Exoplanet Archive
* Confirmed Planets Discovered by TESS refers to the number planets that have been published in the refereed astronomical literature.
* TESS Project Candidates refers to the total number of transit-like events that appear to be astrophysical in origin, including false positives as identified by the TESS Project.
* TESS Project Candidates Yet To Be Confirmed refers to the number of TESS Project Candidates that have not yet been dispositioned as a Confirmed Planet or False Positive.
We're in good company on this list of 13 nonprofits working on pollution solutions! Luckily, #lightpollution is the easiest form of pollution to reverse; the actions we take today have an impact on our night tomorrow. @1PercentFTP https://t.co/4xW4iskAKg
— IDA Dark-Sky (@IDADarkSky) November 27, 2019
NASA Using Virtual Reality in 1993!
In preparation for STS-61, the first @NASAHubble Space Telescope servicing mission, which launched #OTD in 1993, @NASA Astronaut Jeff Hoffman wears a virtual reality helmet and gloves to practice positioning the Space Shuttle Endeavour's robotic arm.
VR - not new for NASA. pic.twitter.com/Sx73qKlIcd
— NASA History Office (@NASAhistory) December 2, 2019
New, Scattered-Light View of Planet-Forming Disks
A New, Scattered-Light View of Planet-Forming Disks https://t.co/xb9Ebex9hC pic.twitter.com/VP2VROwgxw
— Prof. Abel Méndez (@ProfAbelMendez) December 3, 2019
Apps used for this post:
NASA Eyes on the Solar System: an immersive 3D solar system and space mission simulator - free for the PC /MAC. I maintain the unofficial NASA Eyes Facebook page.
Stellarium: a free open source planetarium app for PC/MAC/Linux. It's a great tool for planning observing sessions. A web-based version of Stellarium is also available.
Universe Sandbox: a space simulator that merges real-time gravity, climate, collision, and material interactions to reveal the beauty of our universe and the fragility of our planet. Includes VR support.
SpaceEngine: a free 3D Universe Simulator for Windows. Steam version with VR support available.
Kerbal Space Program: Create and manage your own space program; build and launch rockets, aircraft, space planes, space probes, landers, rovers and more!
Section header image credits:
The Sky - Stellarium / Bob Trembley
Observing Target - Turn Left at Orion / M. Skirvin
The Moon - NASA/JPL-Caltech
The Sun - NASA/JPL-Caltech
Asteroids - NASA/JPL-Caltech
Fireballs - Credited to YouTube
Comets - Comet P/Halley, March 8, 1986, W. Liller
The Solar System - NASA Eyes on the Solar System / Bob Trembley
Spacecraft News - NASA Eyes on the Solar System / Bob Trembley
Exoplanets - Space Engine / Bob Trembley
Light Pollution - NASA's Black Marble
The Universe - Universe Today