Questions tagged [earth-observation]

questions about the observation of the planet Earth from space, usually for scientific, technical, or other well-defined reasons, or about the spacecraft that do this. This tag is usually used for systematic observations, but it could also apply to a questions on specific images or photos observing something unusual requiring analysis.

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70 votes
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Why did it take so long to notice that the ozone layer had holes in it? Which satellite provided the data?

Wikipedia says: The discovery of the annual depletion of ozone above the Antarctic was first announced by Joe Farman, Brian Gardiner and Jonathan Shanklin, in a paper which appeared in Nature on May ...
uhoh's user avatar
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49 votes
2 answers
14k views

What caused this bright light from the ground at night seen from the ISS?

The music video on the NASA Johnson YouTube channel The Sound (& Visions) of Silence shows images and video of Earth taken from the ISS by astronauts Sergey Ryazanskiy, Paolo Nespoli, and ...
uhoh's user avatar
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33 votes
7 answers
5k views

Is it possible to see animals from space?

Will satellite imagery be able to see the backs of big animals such as lions, tigers, elephants, horses or zebras from space when they venture out in the open? I've not been able to find satellite ...
Nederealm's user avatar
  • 435
33 votes
2 answers
8k views

Has anyone in space seen or photographed a simple laser pointer from Earth?

In the question How to make a green LED as visually bright as a 0 magnitude star? I worked out that a 100 mA green LED with a 10° half-angle 18 kilometers away would be as bright as a 0th magnitude ...
uhoh's user avatar
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30 votes
4 answers
8k views

Could Apollo astronauts see city lights from the Moon?

You can see city lights from orbit on the night side of Earth. A lot of science fiction (yes, sorry... it's one of those questions) has dialogue such as "on a clear night you can see XYZ city on ...
Michael Stachowsky's user avatar
23 votes
3 answers
4k views

Could a spy satellite in orbit be recommissioned to do astronomy?

Since the National Reconnaissance Office offered NASA a left-over Hubble sized mirror that might be used for the WFIRST space telescope, I wonder if the NRO has satellites in operation that could do ...
LocalFluff's user avatar
20 votes
2 answers
4k views

What is the name of the area on Earth which can be observed from a satellite?

The following image shows Earth and the trajectory of the ISS. A green line indicates which part of the earth can be observed from the ISS simultaneously. What is the name of this line or this area?
rul30's user avatar
  • 397
20 votes
1 answer
4k views

Has the Earth's red atmosphere rim ever been photographed?

In the Wikipedia article on Lunar eclipse there's given an image of how the Earth would look from the eclipsed Moon: This is obviously a schematic drawing. So I wonder, has the Earth ever been ...
Ruslan's user avatar
  • 439
19 votes
3 answers
6k views

Minimum number of satellites to image the entirety of Earth's surface at all times

The simplest solution would be a tetrahedron, but as the satellites all need to orbit in circles, it seems this configuration would only guarantee full coverage at one time. For simplicity, there's ...
Guillochon's user avatar
19 votes
1 answer
2k views

When did photographic film stop being used in satellites?

Some early observation satellites took pictures on photographic film and the film was dropped towards Earth and picked up by airplanes (e.g. Corona). What was the last satellite to use photographic ...
usernumber's user avatar
  • 5,048
17 votes
2 answers
2k views

What is the highest frequency at which Earth is, or has been, observed from space?

Earth observation from space occurs throughout the electromagnetic spectrum. With my meteorological bias, I until recently believed it wasn't at frequencies higher than UV, but the X-Ray detector ...
gerrit's user avatar
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14 votes
4 answers
8k views

How many photographs are there of the whole Earth?

Most of the representations of the Earth from space that one sees are inventions, meant to clearly show the things people most want to see - the outlines of the continents, instead of mostly clouds as ...
kim holder's user avatar
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13 votes
1 answer
1k views

What is your name? What is your quest? What is the story behind Satellite 1963-38C?

Source see also the page On Possible Electric Phenomena in Solar Systems and Nebulae By Kristian Birkeland extracted from The Norwegian Aurora Polaris Expedition 1902-1903 (Book) Wikipedia's ...
uhoh's user avatar
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13 votes
1 answer
2k views

At what minimum distance does the Earth appear star-like to the naked eye?

At what distance does the Earth become indistinguishable from stars and other planets to the naked eye, like the Pale Blue Dot or like Venus or Mars visible from Earth? Dot-like rather than spherical. ...
LoveForChrist's user avatar
12 votes
2 answers
3k views

Which high-resolution Earth-facing satellites transmit data to the public in realtime?

Some NASA satellites such as LASCO transmit images which are viewable by the public in real time. Are there any high-resolution Earth-facing satellites that also are viewable by the public in real ...
dotancohen's user avatar
  • 6,754
12 votes
3 answers
2k views

Do Starlink satellites have cameras?

Obviously, Starlink satellites are equipped with sensors for attitude and location detection (like a star tracker or sun tracker) but I'm wondering if they have with any direct Earth observation ...
Dragongeek's user avatar
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11 votes
1 answer
928 views

Star-shaped artifacts in SAR images of the "Suez Canal traffic jam seen from space"

Wikipedia's 2021 Suez Canal obstruction links to the Sentinel-1 synthetic aperture radar (SAR) image of the Traffic jam in the Gulf of Suez caused by the obstruction as seen by the Sentinel-1 ...
uhoh's user avatar
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10 votes
3 answers
1k views

Could an ISS astronaut photograph something like this 1km "Van Gogh" if they knew it was there?

At the end of December 2015, a giant "painting" made of 4 million color-sorted recycled bottles was put on display in Keelung, Taiwan. The Indian Express says it's 53 hectares, which is 530,000 square ...
uhoh's user avatar
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10 votes
4 answers
685 views

Single-shot Blue Marble pictures

I was quite surprised to read in today's Earth Observatory Picture of the Day that the DSCOVR spacecraft, currently en route to the $L_1$ Lagrange point, will be the first spacecraft able to see the ...
E.P.'s user avatar
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10 votes
2 answers
4k views

What is this huge, red, blinking light structure on Earth seen from the ISS in this video?

The video ESA video Progress launch timelapse seen from space is of course striking for many reasons. However there is a strange, blinking light structure on Earth that's quite puzzling! I've added a ...
uhoh's user avatar
  • 149k
10 votes
2 answers
626 views

Will SMAP produce predictable satellite flares visible to the naked eye from the surface of the Earth?

The SMAP (Soil Moisture Active/Passive) satellite just deployed its 6 meters (19.7-foot) mesh reflector antenna today. The satellite orbits the Earth in Sun-synchronous retrograde near-polar, near ...
TildalWave's user avatar
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10 votes
1 answer
948 views

Is Google Earth's view from space geometrically correct?

Google maps has a new (to me) feature, and it is pretty awesome! If you start at maps.google.com, switch to Earth view, and zoom all the way out, you get a view something like the one shown below. ...
Chris Mueller's user avatar
9 votes
2 answers
537 views

Can ISS astronauts see the lava from the Kilauea volcano at night?

The google news said "Lava from the Kilauea volcano can be seen from space" but it just links to the YouTube video of the same name. The screen shot of the video below shows a small ESA credit at the ...
uhoh's user avatar
  • 149k
9 votes
1 answer
462 views

Why is the Aeolus space laser losing power so quickly?

The BBC News article Aeolus: Wind-mapping space laser is losing power says that Europe's Aeolus satellite was launched last year to gather data to improve weather forecasts, and its observations have ...
uhoh's user avatar
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8 votes
1 answer
1k views

Why does Himawari-8 have problems with the Sun from 19th February to 19th April?

This weather site uses provides meteorological imaging from the Himawari-8 Earth observing satellite in GEO. https://www.cwb.gov.tw/eng/ The web site contains the following item: ...
uhoh's user avatar
  • 149k
8 votes
2 answers
628 views

How were video tape recorders adapted to work in orbit in 1962?

Livescience's Satellite spies gigantic 'fuzzball' clouds spreading near Australia coast says: Actinoform clouds were first captured by NASA’s Television Infrared Observation Satellite V in 1962, but ...
uhoh's user avatar
  • 149k
7 votes
2 answers
349 views

If all Starlink satellites had phone tier cameras & simple scopes, could images processed by their super-resolution imaging network be competitive?

I was wondering; if all Starlink satellites had high-end cellphone quality cameras modules on simple telescopes, could the resulting images be combined and processed in such a way that a super-...
AggroFrizzy's user avatar
7 votes
2 answers
470 views

What exactly gives a larger field of view to the donated "spy" telescopes that NASA may send to Mars? How much larger?

This answer to Could one of the interstellar probes discover Planet IX by accident? links to Space.com's NASA May Launch Donated Spy Satellite Telescope to Mars which says: An unexpected gift The two ...
uhoh's user avatar
  • 149k
7 votes
1 answer
182 views

Do crew movements or movement of other objects ever affect space or Earth observation experiments staged on the outside of ISS?

The ISS serves as a platform for both Earth and astronomical observational instrumentation. Do routine movements of the crew or other objects ever cause problems for these observations through ...
uhoh's user avatar
  • 149k
7 votes
1 answer
294 views

How was motion blur mitigated in the early Earth-observation satellites?

The Corona Photographic Surveillance Satellite had one (later two) panning cameras for observations: (Cameras on Corona - source) The cameras panned over a 70 degree arc perpendicular to the flight ...
Ludo's user avatar
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7 votes
1 answer
355 views

Could spy satellites be blinded? For example by search lights?

Assume that Doctor Evil insists on dancing outdoors although he has been forbidden by the UN to do so. And that spy satellites can observe this against Doctor Evil's volition. Could Doctor Evil keep ...
LocalFluff's user avatar
7 votes
0 answers
98 views

Does NOAA still plan to deploy all twelve Cosmic-2 GPS radio occultation satellites?

In the 2014 Space News interview of Jim Bridenstine (now NASA administrator, then member of the US house of representatives for Oklahoma) Q&A With Rep. Jim Bridenstine (R-Okla.) appears: Space ...
uhoh's user avatar
  • 149k
7 votes
0 answers
328 views

Have LAGEOS' germanium corner cube reflectors ever been used?

When I was writing this answer about the LAGEOS satellites, I notices that four of the over four hundred corner reflectors are made of optical germanium rather than fused silica. Fused silica (FS) ...
uhoh's user avatar
  • 149k
6 votes
2 answers
667 views

Hovering Carbonite! Why do these satellite videos of Earth appear to be made from a geostationary location?

The BBC News article UK satellite makes HD colour movies of Earth has led me to a series of YouTube videos as well recorded by the Carbonite-2 spacecraft built by Surrey Satellite Technology to be ...
uhoh's user avatar
  • 149k
6 votes
1 answer
1k views

How is satellite data used to find drug crops?

Almost all leaves are a pretty similar shade of green, and from the altitude of a satellite a single pixel must be bigger than a whole bush. Yet satellite imagery has become central to detecting ...
kim holder's user avatar
  • 21.4k
6 votes
1 answer
299 views

Sentinel-2C and frequency of acquisition

Sentinel-2C, the third Sentinel-2 satellite of the Copernicus program, is planned to be launched in 2024. Currently, the Copernicus SENTINEL-2 mission "comprises a constellation of two polar-...
AlixL's user avatar
  • 163
6 votes
1 answer
467 views

Why didn't SpaceX see that geomagnetic storm coming? Was this a fluke or could this happen more frequently in the future? (R.I.P. 40 lost starlinks)

Ars Technica's SpaceX loses up to 40 satellites to geomagnetic storm after Starlink launch explains that a geomagnetic storm heated Earth's upper atmosphere (circa 200 km) so much that the aerodynamic ...
uhoh's user avatar
  • 149k
6 votes
1 answer
164 views

Inexplicable Offset in Satellite Laser Ranging (SLR) observations

I am struggling with the implementation of a Satellite Laser Ranging (SLR) validation tool. The situation is as follows: I am provided with a framework which gives me the position of a SLR ...
lenxn's user avatar
  • 163
6 votes
1 answer
108 views

How can satellites measure the energy of individual ~100 MeV gamma ray photons with reasonable certainty

This answer states: From the AstroMEV website: Terrestrial gamma-ray flashes (TGFs) are high-energy photons originating from the Earth's atmosphere in association with thunderstorm activity. TGFs ...
uhoh's user avatar
  • 149k
6 votes
1 answer
1k views

Has an astronaut ever seen pixies, ELVEs, sprites or blue jets (without a camera)?

The NASA Science video ScienceCasts: A Display of Lights Above the Storm shows several examples of Transient Luminous Events (TLEs) (Upper Atmospheric Lightning) being filmed by high-sensitivity ...
uhoh's user avatar
  • 149k
5 votes
7 answers
1k views

How can the CYGNSS spacecrafts (actually) measure ocean roughness?

The Cyclone Global Navigation Satellite System is a group of 8 smallsats which will orbit near the equator (inc=30°) and work as a constellation to take data on typhoons and hurricanes. While they are ...
uhoh's user avatar
  • 149k
5 votes
3 answers
357 views

Is there a database of recent satellite images which will allow me to estimate how much of Mariopol has been destroyed?

In the news I often see satellite images from Maxar Technologies showing a neighborhood or sector of Mariupol to have been destroyed in shelling. However, I would like a more comprehensive view of the ...
Tom's user avatar
  • 151
5 votes
2 answers
246 views

Is it possible to deliver enough LEO satellites with one launch to substitute for one in GEO?

Rough estimates shows that having around one hundred satellites would be enough to observe a single spot on Earth continuously and via peer to peer communication deliver that information to an earth-...
Anbu Agarwal's user avatar
5 votes
1 answer
749 views

How can I calculate the Characteristic Energy to Sun-Earth L1?

Alternatively, does anyone know it? I'm asking in regards to the upcoming DSCOVR (Deep Space Climate Observatory) mission scheduled to launch aboard a Falcon 9 v1.1 rocket in January 2015. DSCOVR is ...
marked-down's user avatar
  • 8,921
5 votes
1 answer
1k views

what is revisit rate

I want to understand what the revisit rate is. If the payload is required to make the revisit rate of 5 hours. The orbit is LEO (altitude less than 2000 kms). What does this mean? Revisit time - the ...
geetha's user avatar
  • 251
5 votes
1 answer
439 views

How many (presumably friendly) lasers are being shot at us from space? (pew! pew!)

Example: at first they could not decide which of the green laser-shooting satellites was responsible! Too many to choose from? See Science Alert's February 9, 2023, Ominous Green Lasers Shot Over ...
uhoh's user avatar
  • 149k
5 votes
2 answers
268 views

Why are images from DSCOVR EPIC unavailable for certain dates?

I am in love with the images available at https://epic.gsfc.nasa.gov/ taken from the DSCOVR satellite. I am curious though as to why some dates are unavailable to select. The calendar date picker ...
Mike's user avatar
  • 51
5 votes
1 answer
212 views

Time of satellite passing overhead

Curious lay person here... I download and analyze Sentinel-2 imagery for a variety of mapping tasks. According to the Sentinel mission description webpage: The Sentinel-2 mission orbit is sun-...
Stu Smith's user avatar
  • 453
5 votes
1 answer
2k views

Cost of an earth observation cubesat satellite like Planet Labs' Doves?

With the cubesat standard and more and more components being available off the shelf, this should really bring down the price of building a (simple) earth observation platform. I am curious how low a ...
Thomas's user avatar
  • 231
5 votes
1 answer
202 views

Study "earthquake" lights from satellite videos

A recent youtube video, "Unexplained Earthquake Light Phenomenon Finally Captured on Camera", by Anton Petrov (who I have a lot of respect for as a science reporter) shows numerous videos of ...
tckosvic's user avatar
  • 2,272