-
#40
by
ccdengr
on 13 Jun, 2018 14:16
-
-
#41
by
zhangmdev
on 13 Jun, 2018 14:45
-
My understanding is, to estimate how much light is attenuated after passing through the media, i.e. the Mars atmosphere, need to estimate the transmittance of the media based on the brightness of the Sun in those tau images, calibrated against its brightness in a clear sky, of the same solar elevation angle.
https://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law
-
#42
by
as58
on 13 Jun, 2018 14:57
-
https://en.wikipedia.org/wiki/Optical_depth under "atmospheric sciences"
Thanks. So apparently in atmospheric (and I guess also planetary) science tau, without further qualification, means optical depth towards the zenith.
-
#43
by
redliox
on 13 Jun, 2018 15:21
-
"For sols 1236-1242 (July 16-22, 2007), the skies were so dark that Opportunity could not muster enough power to perform its usual tau measurements.Credit: NASA / JPL / Cornell / animation by Emily Lakdawalla "
http://planetary.org/explore/space-topics/space-missions/mer-updates/2007/07-31-mer-update.html
The situation is much worse than it was 11 years ago.
Fingers crossed for Opportunity, but something this large, if anything, sadly might be the final nail in the coffin. We'll only know for sure after a few days.
-
#44
by
Ilikeboosterrockets
on 13 Jun, 2018 16:08
-
-
#45
by
Nomadd
on 13 Jun, 2018 16:50
-
-
#46
by
Orbiter
on 13 Jun, 2018 16:53
-
This dust storm is so intense even amateurs can easily spot it in a small telescope. I've been watching it with my 8" dobsonian and Syrtis major, one of the more prominent features on Mars, is almost completely obscured. This is turning into a global event.
-
#47
by
1
on 13 Jun, 2018 17:33
-
JPL news conference going live.
-
#48
by
Chris Bergin
on 13 Jun, 2018 17:48
-
How the Mars dust storm caught Opportunity right in the middle of it.
-
#49
by
Chris Bergin
on 13 Jun, 2018 17:57
-
Sounds positive. Won't breach the coldest allowable temperatures. Won't be "buried alive" (reporter question). Can hunker down for a long time and recharge when the sky clears. The concern is how long they can continue in low power (and then to wake up/communicate correctly).
-
#50
by
Chris Bergin
on 13 Jun, 2018 18:12
-
"We're very concerned. The team has a very tight bond with the Rover. It's like a loved one (and said an old grandma, due to the age) in the hospital with a coma."
-
#51
by
Ilikeboosterrockets
on 13 Jun, 2018 18:29
-
Sounds positive. Won't breach the coldest allowable temperatures. Won't be "buried alive" (reporter question). Can hunker down for a long time and recharge when the sky clears. The concern is how long they can continue in low power (and then to wake up/communicate correctly).
"Won't breach the coldest allowable temperatures" as long as the heaters stay active, correct? Or can the rover survive without the heaters? And do we know if the rover has enough reserve power to keep the heaters active for weeks/months?
-
#52
by
1
on 13 Jun, 2018 18:32
-
Sounds positive. Won't breach the coldest allowable temperatures. Won't be "buried alive" (reporter question). Can hunker down for a long time and recharge when the sky clears. The concern is how long they can continue in low power (and then to wake up/communicate correctly).
"Won't breach the coldest allowable temperatures" as long as the heaters stay active, correct? Or can the rover survive without the heaters? And do we know if the rover has enough reserve power to keep the heaters active for weeks/months?
Mentioned a few times, but since ambient temperatures aren't expected to drop below minimum, primary concern is providing sufficient power to the mission clock. All electronics, including heaters, can be deactivated. Further loss of power will cause a 'clock fault' that will cause the rover to lose track of what time it is and will cause erratic behavior in terms in communications. Team is prepared for that possibility and will hopefully be able to restore proper behavior if that happens.
-
#53
by
Yellowstone10
on 13 Jun, 2018 19:05
-
"Won't breach the coldest allowable temperatures" as long as the heaters stay active, correct? Or can the rover survive without the heaters? And do we know if the rover has enough reserve power to keep the heaters active for weeks/months?
The electric heaters are off when the rover is in a low-power fault, but it also has 8 radioisotope heater units that put out about 1 watt each. In today's briefing, they said that between those heaters and the ambient temperature, the rover is expected to stabilize at -36 °C. It's designed to operate down to -40 °C, so it should be good.
-
#54
by
FutureSpaceTourist
on 13 Jun, 2018 19:20
-
-
#55
by
Star One
on 13 Jun, 2018 19:58
-
-
#56
by
theinternetftw
on 13 Jun, 2018 20:01
-
Here are the last two slides that were in the presentation, one of Curiosity's observation of the planet-wide storm, and another of the storm spreading animation.
edit: clarifying what the first slide is.
-
#57
by
Don2
on 13 Jun, 2018 23:27
-
The dust storm is good news for some: From Jan 2018 article:
Some Mars experts are eager and optimistic for a dust storm this year to grow so grand it darkens skies around the entire Red Planet.
This biggest type of phenomenon in the environment of modern Mars could be examined as never before possible, using the combination of spacecraft now at Mars.
A study published this week based on observations by NASA's Mars Reconnaissance Orbiter (MRO) during the most recent Martian global dust storm -- in 2007 -- suggests such storms play a role in the ongoing process of gas escaping from the top of Mars' atmosphere. That process long ago transformed wetter, warmer ancient Mars into today's arid, frozen planet.
https://www.nasa.gov/feature/jpl/dust-storms-linked-to-gas-escape-from-mars-atmosphereOn another topic, the best positioned camera to monitor this dust storm is probably the Indian one. Is there any chance we might see anything from them?
-
#58
by
DaveS
on 16 Aug, 2018 09:53
-
There's good news today! DSS-34 has detected a strong carrier signal from Opportunity! Active commanding is currently in progress.
Edit: Based on the frequency and data rate of the initial AOS, this was from the rover's steerable high gain antenna (6.00 Mb/s, 8.44 GHz).
-
#59
by
DaveS
on 16 Aug, 2018 10:23
-
The Opportunity downlink signal disappeared for a while indicating most likely that the playback of stored data has been completed. This is an indication that the rover is following a preset schedule of commands of what do to when ever it recovers from a low-power fault.
The signal has now returned some 18 minutes after active commanding began which shows that the rover is alive and can be commanded from the ground.