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#satellite

29 posts21 participants1 post today
Public
TomKrajci 🇺🇦 🏳️‍🌈 🏳️‍⚧️

Blue satellite?

I captured these images last night while my cameras were on patrol for Lyrids meteors.

They appear to show a blue satellite trail around 9:19PM Mountain Daylight Time, as seen from the Sacramento mountains of southern New Mexico.

Note that camera's color balance was set to 'daylight' and in the first image another, fainter, satellite trail is also visible...it's not blue, it's a typical color. Also note star colors. This camera over the years has shown itself to be accurate in rendering color in night/day photos.

Have others seen this before?

Sony a6300 camera, 23mm lens at f/1.4, ISO 800, 30 second exposures, using intervalometer with 31-second timing. Camera pointed near zenith. (Note that this lens, at f/1.4, shows stars with coma and astigmatism in the corners of the frame...so the stars look as if they have wings/tails.)

nova.astrometry.net/user_image

Please boost/share widely.

#Satellite #Mystery #Photography #Meteors #Lyrids

@sundogplanets

First image of blue satellite trail. Camera is pointed near the zenith.
Second satellite image. Trail fades to invisibility in right half of image.
Public
La Griffe

L'Ukraine cherche des alternatives européennes à Starlink.

C’est une éventualité qui pourrait faire basculer la guerre en #ukraine La menace de couper l’accès de #Kiev au réseau américain de satellites #Starlink aurait de lourdes conséquences. Le caractère imprévisible de son propriétaire, #musk inquiète Kiev et l' #ue Pour éviter ce possible scénario, les autorités ukrainiennes cherchent des alternatives auprès de l'UE. fr.euronews.com/my-europe/2025

#satellite#Russie#espace
Public
MediaFaro Analysis

Govsatcom, Eutelsat, Iris2: Ukraine seeks European alternatives to Starlink.

The American Starlink satellite network is currently essential to the Ukrainian military forces on the ground. The threat to cut off Kyiv's access to the Starlink satellite network could have far-reaching consequences for the war.

To avoid this, Ukrainian authorities are seeking alternatives from the EU.

mediafaro.org/article/20250422

The Ariane 6 rocket launches from the European spaceport in Kourou, French Guiana. | Copyright AP Photo
Euronews · Govsatcom, Eutelsat, Iris2: Ukraine seeks European alternatives to Starlink.By Gregoire Lory
#Ukraine#WarInUkraine#Starlink
Public *
anlomedad

"Satellite-based evidence of recent decline in global forest recovery rate from tree mortality events" by Yuchao Yan et al 2025.
Fascinating and educational. All the more for us in Germany and Finland, and likely other Europeans, whose forests morphed from CO2 sink to source. The study ends with 2020 data tho, Europe with 2018.
Only non-fire mortality events were analyzed.
I learned how recovery after a drought-driven forest mortality event depends on🌡️💧during recovery; not so much the event severity.
nature.com/articles/s41477-025
Free e-pdf provided by one of the authors:
rdcu.be/eigV4

Don't know about you but to me, a paper is particularly "good" if I'm left with a host of new pressing questions. "Why did they..? Was it maybe ..? What if it had been...?"

For a recovery phase, they differentiate between recovery of the canopy greening and recovery of water content in the canopy. Both are based on satellite obs only. And if a satellite image suggests greening is recovered to pre-mortality level, it might not actually be re-greening from recovered old or new young trees but could be merely dense shrubbery. The Greening parameter is often used to glean carbon stock. Shrubs have less biomass=less carbon than trees.
The water content in the canopy then somehow helps to clarify the actual recovery state. How? 🤷‍♀️

Water content in canopy always takes far longer to recover than re-greening.
Longer = years and years longer.
Always = in the 1980s as well. Which I take as: that's the normal baseline behaviour for a given biome, a given latitude zone, a given climate zone, a given elevation, a given human intervention etc.

Supplementary Fig. 5. c and d show numbers for North America and Tropics static-content.springer.com/es .
Recovery Time in years for water in canopy in North America
in the 1990s took 2 - 12, average 6.
in the 2000s took 2 - 18, average 9.

in the Tropics:
in the 1990s took 2 - 12, average 6.
in the 2000s took 2 - 11, average 7.

Europe is missing an extra whiskers plot. Maybe they saved this for their next paper. But European events are included up to 2018, if I got it right.

With all the factors to be considered, and bias in numbers of events in any given factor, making recovery comparable across regions, across biomes, across climate zones, a global average doesn't seem very useful.
However, here are the global numbers from Figure 1d for
Recovery time RT for water in canopy. In the 1980s RT was between 2 and 15, average 8, median 6 .
In the 1990s, RT was 2 - 22, average 8, median 6.
In the 2000s, RT was 2 - 20, average 9, median 9 years.

Am curious wrt the missing potential cause for the greatly reduced RecoveryTime in the 2010s in Fig.1d. Is that an artefact of the shortened observation time for these 10 most recent mortality yrs?
And Greening recovered astonishingly quickly in the 2010s. is it the high CO2 fertilisation or a regional bias from the events in this period?

NatureSatellite-based evidence of recent decline in global forest recovery rate from tree mortality events - Nature PlantsSatellite data show declining global forest recovery from tree mortality since the 1990s, driven by warming and water scarcity. Canopy water recovers slower than greenness, stressing the need for a multifaceted approach to assessing recovery.
#climate#ecosystem#drought
Public
Benjamin Carr, Ph.D. 👨🏻‍💻🧬

Small #ocean swirls may have an outsized affect on #climate, #NASA #satellite shows
Surface Water and Ocean Topography (#SWOT) satellite lets scientists observe small-scale #eddies and waves for the first time. Its Ka-band Radar Interferometer scans 120-km-wide swaths of sea surface height, delivering two-dimensional measurements with far greater resolution and lower noise than earlier altimeters. The satellite's 21-day orbit enables repeated global coverage.
theregister.com/2025/04/17/sma

The Register · Small ocean swirls may have an outsized affect on climate, NASA satellite showsBy Lindsay Clark
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