5-hour pinhole exposure of total eclipse

A pinhole image of the sun’s path across the sky, made over 5 hours on August 21, 2017, showing the sun going dark at mid-eclipse. Image by Ian Hennes.

A few years ago, we published an image from Ian Hennes of Medicine Hat, Alberta, Canada, showing the sun’s shifting path across the sky from a summer to a winter solstice. Here’s another similar image from Ian, but it’s the sun’s path for just 5 hours of one day – the day of the August 21, 2017 total solar eclipse – and it clearly shows the totally eclipsed sun going dark over Ian’s observing location, just north of Rexburg, Idaho. Ian wrote:

You had previously enjoyed my ultra-long pinhole exposure from solstice to solstice, so I thought you might like the pinhole photo I took at the total eclipse. It is a 5-hour, single exposure, using only a pinhole camera. Eclipse is clearly visible.

Ian said he used the following equipment to obtain this image:

Beer can. Photo paper. Pin hole.

I take a beer can, put photo paper inside, and make a tiny pinhole in the can. Then I place it where I want to expose, tape it solid, and leave it for hours in this case, but weeks or months in other cases. Then I take the can down, remove the paper, and scan it into the computer. The sun has burned a dark image on the paper, so I ‘invert’ it with software to ‘develop’ the negative image.

That’s it. It’s a unique style of photography that I’ve been doing the past few years, around my home town and while traveling.

Thanks for looking.

Here’s an image of Ian’s setup on his brother-in-law’s jeep. There’s a tiny pinhole in the middle of the blue area on the can. You can also see he used another can, cut in half, for the lid. No light can enter, except through the pinhole landing on the paper. This setup exposed the eclipse for 5 hours straight, one exposure, and resulted in the image at the top of this page. Photo by Ian Hennes.

By the way, want to make your own pinhole viewing system – with a cereal box – for the next eclipse? On his Facebook page, Ian recommended the following video:

Bottom line: Long-exposure pinhole photo by Ian Hennes, of the sun moving across the sky on August 21, 2017. You can see when the eclipse happened, because, on the photo, the sun goes dark. Thank you, Ian!

from EarthSky http://ift.tt/2wLuoqW

A pinhole image of the sun’s path across the sky, made over 5 hours on August 21, 2017, showing the sun going dark at mid-eclipse. Image by Ian Hennes.

A few years ago, we published an image from Ian Hennes of Medicine Hat, Alberta, Canada, showing the sun’s shifting path across the sky from a summer to a winter solstice. Here’s another similar image from Ian, but it’s the sun’s path for just 5 hours of one day – the day of the August 21, 2017 total solar eclipse – and it clearly shows the totally eclipsed sun going dark over Ian’s observing location, just north of Rexburg, Idaho. Ian wrote:

You had previously enjoyed my ultra-long pinhole exposure from solstice to solstice, so I thought you might like the pinhole photo I took at the total eclipse. It is a 5-hour, single exposure, using only a pinhole camera. Eclipse is clearly visible.

Ian said he used the following equipment to obtain this image:

Beer can. Photo paper. Pin hole.

I take a beer can, put photo paper inside, and make a tiny pinhole in the can. Then I place it where I want to expose, tape it solid, and leave it for hours in this case, but weeks or months in other cases. Then I take the can down, remove the paper, and scan it into the computer. The sun has burned a dark image on the paper, so I ‘invert’ it with software to ‘develop’ the negative image.

That’s it. It’s a unique style of photography that I’ve been doing the past few years, around my home town and while traveling.

Thanks for looking.

Here’s an image of Ian’s setup on his brother-in-law’s jeep. There’s a tiny pinhole in the middle of the blue area on the can. You can also see he used another can, cut in half, for the lid. No light can enter, except through the pinhole landing on the paper. This setup exposed the eclipse for 5 hours straight, one exposure, and resulted in the image at the top of this page. Photo by Ian Hennes.

By the way, want to make your own pinhole viewing system – with a cereal box – for the next eclipse? On his Facebook page, Ian recommended the following video:

Bottom line: Long-exposure pinhole photo by Ian Hennes, of the sun moving across the sky on August 21, 2017. You can see when the eclipse happened, because, on the photo, the sun goes dark. Thank you, Ian!

from EarthSky http://ift.tt/2wLuoqW

Moon and star Antares on August 28

Tonight – August 28, 2017 – let the moon introduce you to Antares. It’s a red star and the brightest star in the constellation Scorpius the Scorpion. Look first for the moon, and the nearby bright star will be Antares. The other bright starlike object making a triangle with the moon and Antares tonight will be Saturn, 6th planet outward from the sun in our own solar system.

You can distinguish Antares from Saturn by color. Antares, the heart of the Scorpion, glows red while Saturn displays a golden color. If you have difficulty discerning color with the eye alone, try your luck with binoculars.

Any red-looking star that you can see with the unaided eye is either a red giant or red supergiant star. Antares is a red supergiant. This star, which is in the autumn of its years, is expected to explode as a supernova one of these days. No telling when that will be, however. It could happen tomorrow or a million years from now.

Although Antares lies way out there, at some 600 light-years distant, this star easily shines at 1st-magnitude brightness. In order to beam so brightly in our sky, this star must be extremely luminous, that is, intrinsically very brilliant as opposed to merely appearing bright because of a nearer distance.

Antares’ red color indicates a relatively cool surface temperature, and cool stars shine less brilliantly than hot stars of the same size. But Antares is just so big! Its sheer size makes this star more luminous than many stars with higher surface temperatures.

Just how large is this incredible star? It’s not known with absolute certainty, but its radius is thought to be about 3 times the Earth’s distance from the sun (3 astronomical units). That’s about 3/5th the way from the sun to the orbit of Jupiter, the 5th planet outward from the sun. The radius of Antares is the equivalent of approximately 650 solar radii.

Presuming a radius of 650 solar radii and therefore a diameter of 650 solar diameters, that means the surface area of Antares exceeds that of our sun by some 122,500 times (Antares’ surface area = 650 x 650 = 122,500 solar). But Antares’ volume is actually a few hundred million times greater than the sun’s (Antares’ volume = 650 x 650 x 650 = 271,630,000 solar). And just to think that the sun has the volume of 1,300,000 Earths!

Bottom line: Tonight – August 28 – let the moon be your guide to Antares, a red supergiant star whose humongous size is truly difficult to fathom!

from EarthSky http://ift.tt/2vgZKnz

Tonight – August 28, 2017 – let the moon introduce you to Antares. It’s a red star and the brightest star in the constellation Scorpius the Scorpion. Look first for the moon, and the nearby bright star will be Antares. The other bright starlike object making a triangle with the moon and Antares tonight will be Saturn, 6th planet outward from the sun in our own solar system.

You can distinguish Antares from Saturn by color. Antares, the heart of the Scorpion, glows red while Saturn displays a golden color. If you have difficulty discerning color with the eye alone, try your luck with binoculars.

Any red-looking star that you can see with the unaided eye is either a red giant or red supergiant star. Antares is a red supergiant. This star, which is in the autumn of its years, is expected to explode as a supernova one of these days. No telling when that will be, however. It could happen tomorrow or a million years from now.

Although Antares lies way out there, at some 600 light-years distant, this star easily shines at 1st-magnitude brightness. In order to beam so brightly in our sky, this star must be extremely luminous, that is, intrinsically very brilliant as opposed to merely appearing bright because of a nearer distance.

Antares’ red color indicates a relatively cool surface temperature, and cool stars shine less brilliantly than hot stars of the same size. But Antares is just so big! Its sheer size makes this star more luminous than many stars with higher surface temperatures.

Just how large is this incredible star? It’s not known with absolute certainty, but its radius is thought to be about 3 times the Earth’s distance from the sun (3 astronomical units). That’s about 3/5th the way from the sun to the orbit of Jupiter, the 5th planet outward from the sun. The radius of Antares is the equivalent of approximately 650 solar radii.

Presuming a radius of 650 solar radii and therefore a diameter of 650 solar diameters, that means the surface area of Antares exceeds that of our sun by some 122,500 times (Antares’ surface area = 650 x 650 = 122,500 solar). But Antares’ volume is actually a few hundred million times greater than the sun’s (Antares’ volume = 650 x 650 x 650 = 271,630,000 solar). And just to think that the sun has the volume of 1,300,000 Earths!

Bottom line: Tonight – August 28 – let the moon be your guide to Antares, a red supergiant star whose humongous size is truly difficult to fathom!

from EarthSky http://ift.tt/2vgZKnz

Jurassic Park 5 – The Eclipse!

Photo taken August 21, 2017 by Fred Espenak – aka Mr. Eclipse – at the Tate Geological Museum at Casper College, Wyoming.

Fred Espenak – the person who generously provided EarthSky readers with so many articles about the August 21 total solar eclipse – wrote:

Get ready for the new summer blockbuster Jurassic Park 5 – The Eclipse.

Not a photoshop composite!

I just couldn’t resist this T-Rex statue in front of the Tate Geological Museum at Casper College so I positioned an automated camera under him to shoot his portrait during the eclipse!

Fred Espenak is a scientist emeritus at Goddard Space Flight Center. For decades, he has been NASA’s expert on eclipses. Fred maintains NASA’s official eclipse web site (eclipse.gsfc.nasa.gov) as well as his personal web site on eclipse photography (mreclipse.com).

from EarthSky http://ift.tt/2vA9HsC

Photo taken August 21, 2017 by Fred Espenak – aka Mr. Eclipse – at the Tate Geological Museum at Casper College, Wyoming.

Fred Espenak – the person who generously provided EarthSky readers with so many articles about the August 21 total solar eclipse – wrote:

Get ready for the new summer blockbuster Jurassic Park 5 – The Eclipse.

Not a photoshop composite!

I just couldn’t resist this T-Rex statue in front of the Tate Geological Museum at Casper College so I positioned an automated camera under him to shoot his portrait during the eclipse!

Fred Espenak is a scientist emeritus at Goddard Space Flight Center. For decades, he has been NASA’s expert on eclipses. Fred maintains NASA’s official eclipse web site (eclipse.gsfc.nasa.gov) as well as his personal web site on eclipse photography (mreclipse.com).

from EarthSky http://ift.tt/2vA9HsC

Orion and Sirius the Dog Star

Tonight – August 27, 2017 – look for a first hint of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, recognizable for the short straight line of three stars that make up Orion’s Belt. And the sky’s brightest star Sirius – sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in the predawn/dawn sky? Many do, at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue – very noticeable!

Orion and the nearby star Sirius will become visible in the evening by northern winter (or southern summer). But presently the Hunter and the Dog Star lord over the southeastern sky at dawn’s first light.

EarthSky astronomy kits are perfect for beginners. Order yours from the EarthSky store.

View larger. | Matthew Chin in Hong Kong caught Sirius and Orion – and other stars – before dawn on August 22, 2016. He calls them “winter stars” because we see them in the evening in Northern Hemisphere winter.

Orion was low in the west after sunset around March and April. By June of each year, this constellation lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago (see our July 30 sky chart). When a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

Because – as Earth orbits the sun – all the stars rise two hours earlier with each passing month, Orion is now higher at dawn than a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius the Dog Star into the sky. After Orion first appears at morning dawn, you can count on Sirius to appear in the morning sky a few weeks later. You should be able to see Sirius at or before dawn right now – unless you live at far northern latitudes. But even there, it won’t be much longer!

Bottom line: Every year in late August, look for Orion the Hunter and Sirius the Dog in the early morning sky! Orion’s three prominent Belt stars always point to Sirius.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Help support EarthSky! Check out the EarthSky store for fun astronomy gifts and tools for all ages!

from EarthSky http://ift.tt/1IbuVvw

Tonight – August 27, 2017 – look for a first hint of the changing season in the predawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, recognizable for the short straight line of three stars that make up Orion’s Belt. And the sky’s brightest star Sirius – sometimes called the Dog Star because it’s part of the constellation Canis Major the Greater Dog – follows Orion into the sky as the predawn darkness gives way to dawn.

Have you noticed a very bright, madly twinkling star in the predawn/dawn sky? Many do, at this time of year. That star is Sirius. It’s so bright that, when it’s low in the sky, it shines with glints of red and flashes of blue – very noticeable!

Orion and the nearby star Sirius will become visible in the evening by northern winter (or southern summer). But presently the Hunter and the Dog Star lord over the southeastern sky at dawn’s first light.

EarthSky astronomy kits are perfect for beginners. Order yours from the EarthSky store.

View larger. | Matthew Chin in Hong Kong caught Sirius and Orion – and other stars – before dawn on August 22, 2016. He calls them “winter stars” because we see them in the evening in Northern Hemisphere winter.

Orion was low in the west after sunset around March and April. By June of each year, this constellation lies behind the sun as seen from Earth. Orion only returned to visibility in Earth’s sky about a month ago (see our July 30 sky chart). When a constellation becomes visible again, after being behind the sun, it always appears in the east before sunrise.

Because – as Earth orbits the sun – all the stars rise two hours earlier with each passing month, Orion is now higher at dawn than a month ago.

As seen from the Northern Hemisphere, Orion precedes Sirius the Dog Star into the sky. After Orion first appears at morning dawn, you can count on Sirius to appear in the morning sky a few weeks later. You should be able to see Sirius at or before dawn right now – unless you live at far northern latitudes. But even there, it won’t be much longer!

Bottom line: Every year in late August, look for Orion the Hunter and Sirius the Dog in the early morning sky! Orion’s three prominent Belt stars always point to Sirius.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Help support EarthSky! Check out the EarthSky store for fun astronomy gifts and tools for all ages!

from EarthSky http://ift.tt/1IbuVvw

Aerobraking: Back to the future

After an approximately 11-week pause due to Mars conjunction and a major software update, ESA’s ExoMars Trace Gas Orbiter (TGO) will restart its aerobraking campaign in September.

Aerobraking, you’ll recall, is the year-long campaign being conducted by TGO using the faint drag of Mars’ upper atmosphere to slow it and lower it into its final science orbit, eliminating the need for it to have carried along hundreds of kilogrammes of fuel on its journey to the Red Planet.

TGO had a summer ‘vacation’ of sorts. On 25 June, it was commanded to suspend its aerobraking campaign and raise its orbit up to a safe altitude (200 km above the surface) to wait out conjunction season .

“We used this period to close out some anomaly reports to get the spacecraft ready to support aerobraking for short orbits, later this year, as well as other technical checks and verifications,” says Spacecraft Operations Manager Peter Schmitz.

Cosmic line up

So what’s a conjunction and why did TGO have to wait it out?

Mars Express conjunction: Line indicates how the Sun blocks or degrades the line-of-sight radio signals between an orbiter, in this case MEX, and Earth. Credit: ESA

As you can see, solar conjunction is the period when “Earth and Mars, in their eternal march around the Sun, are obscured from each other by the fiery orb of the Sun itself. Like dancers on either side of a huge bonfire, the two planets are temporarily invisible to each other (great quote from our friends over at NASA).”

In other words, the presence of the Sun blocks or severely degrades the quality of radio signals passing between ground stations on Earth and spacecraft orbiting, or on, Mars.

Bits can be lost, packets can be dropped and even if signals do get through, and the data bitrates, typically running at hundreds of Kbps up to 2 MB/sec, when TGO communicates with ESA’s New Norcia or Malargüe ground stations, drop to just a few tens of bits per second (a typical home or mobile phone Internet connection is many times faster than this).

During the height of conjunction, it’s difficult to reliably send routine commands to a spacecraft at Mars (for ESA, these comprise TGO and Mars Express; in future it will include the ExoMars 2020 Rover), and communication limitations already start several weeks before the main conjunction period and last until several weeks after.

Further, TGO aerobraking requires the flight control team at ESA’s ESOC mission control centre in Darmstadt, Germany, to send commands and downlink telemetry more or less every day.

“During aerobraking we also need to be able to update our guidance commanding every day due to the unpredictability of the orbit following an aerobraking drag pass,” says Peter.

“So any uncertainty in communication reliability means that aerobraking has to be put on hold.”

This period occurs once every two years, and lasts about two weeks – in this case, 18 July until 4 August – at its peak.

Software gets updated

If waiting out conjunction season was the only consideration, aerobraking could have resumed as soon as mid-August, when communications once again became reliable.

“We decided to use the end of conjunction season as an opportunity to conduct a software upgrade for TGO, which had been in planning since after we initiated the campaign in March this year,” says Peter.

Spacecraft Operations Manager Peter Schmitz gives the thumbs up in the main control room at ESA’s control centre in Darmstadt, Germany, on 19 October 2016, shortly after the ExoMars Trace Gas Orbiter arrived at the Red Planet. Credit: ESA/J. Mai

The operating system improvements take into account lessons learned and glitches identified since the start of aerobraking and ensure that the spacecraft is optimised for the remaining campaign period, when the orbit will become even lower. (Some of the concomitant spacecraft operations challenges will include the orbital period falling to about 2 hours, and communication windows being severely reduced, to only 30-40 min per orbit.)

The new software also updates autonomous reactions in case the star trackers get blinded, ensures safe uplink of recovery command files, tunes monitoring thresholds used for failure detection and improves several recovery actions for several failure scenarios; overall, it will improve general robustness against failures during aerobraking

While your laptop or tablet at home routinely downloads and installs updates to its operating system software with little more than a brief notice not to unplug the device and please wait for a few minutes, upgrading TGO orbiting Mars at some 390 million km is another challenge entirely.

“We uploaded the new software starting on 14 August, sending the new code in four separate batches totalling 3 MB,” says Spacecraft Operations Engineer Johannes Bauer.

In total, it was a three week process to upload the software code, install it on one of the two processor modules, reboot with the new software and then install it on the other processor module.

“We had already been working for some time with our colleagues at Thales Alenia Space to test the new software and prepare for the upgrade, and worked intensively in the week preceding the 21st to get ready.”

The upload took some time, due to the aforementioned low bitrates and due to the necessity to check and verify that the uploaded software was completely and correctly received on board.

The new software was stored on board the back-up memory, and booted into operation, and once verified, the software was uploaded a second time for storage on the redundant memory.

“The spacecraft is now working as expected,” says Johannes.

Walking in all over again

With the update complete, the team are now preparing for the ‘walk-in phase’ to restart aerobraking.

This comprises a series of nine manoeuvres to lower the craft step-wise until it starts ‘feeling’ atmospheric drag, indicating that aerobraking is again underway, and is similar to what was conducted in March this year when the aerobraking campaign initially commenced.

The first manoeuvre – the biggest of the nine with a planned ‘delta-v’ (change in speed) of 5.3 m/sec – is planned for Wednesday, 30 August, at about 07:53 CEST, and will bring the craft down to 140 km altitude at pericentre passage.

The remaining eight manoeuvres will be much smaller, typically running at 0.8 to, later, 0.2 m/sec and occurring every two to four days, and lowering the altitude at pericentre passage by tens and then later just two or three km per burn.

“The target altitude at pericentre passage to restart aerobraking is around 110/115 km on 19 September, but this will depend on actual results and the Martian atmosphere,” says Johannes.

The flight dynamics teams at ESOC will be extremely busy during this period, conducting orbit determinations immediately after each burn to assess the performance and confirm the subsequent manoeuvre plan, all on a very tight schedule.

“It’s taken a lot of effort from the entire flight control team together with excellent support from our colleagues in flight dynamics, the ground stations and data systems, and we’re looking forward to restarting aerobraking,” says Operations Manager Schmitz.

“It means we’ll be that much closer to our final routine orbit and the start of science observations, the ultimate reason why we fly to Mars.”

---

Editor’s note:

During the software upgrades on 21 August, there was a gap in ground station coverage between the ESA deep-space stations in Argentina and Australia lasting about an hour. While not absolutely critical, it was highly desirable to maintain a link with TGO to monitor progress of the software installation and computer reset/reboot taking place on board.

64m antenna Kalyazin Credit: ESA

Due to advantageous geography, the Russian 64 m-diameter antenna at Kalyazin, in the Tver region some 300 km north of Moscow, could step in and provide telemetry downlink between 12:00 and 13:00 Moscow time (11:00- 12:00 CEST; 09:00-10:00 UTC). The reception was successful, and the information was transmitted in real time to ESOC for analysis.

See: Big dishes band together

 

 

 

 

from Rocket Science http://ift.tt/2xC7Y7S
v

After an approximately 11-week pause due to Mars conjunction and a major software update, ESA’s ExoMars Trace Gas Orbiter (TGO) will restart its aerobraking campaign in September.

Aerobraking, you’ll recall, is the year-long campaign being conducted by TGO using the faint drag of Mars’ upper atmosphere to slow it and lower it into its final science orbit, eliminating the need for it to have carried along hundreds of kilogrammes of fuel on its journey to the Red Planet.

TGO had a summer ‘vacation’ of sorts. On 25 June, it was commanded to suspend its aerobraking campaign and raise its orbit up to a safe altitude (200 km above the surface) to wait out conjunction season .

“We used this period to close out some anomaly reports to get the spacecraft ready to support aerobraking for short orbits, later this year, as well as other technical checks and verifications,” says Spacecraft Operations Manager Peter Schmitz.

Cosmic line up

So what’s a conjunction and why did TGO have to wait it out?

Mars Express conjunction: Line indicates how the Sun blocks or degrades the line-of-sight radio signals between an orbiter, in this case MEX, and Earth. Credit: ESA

As you can see, solar conjunction is the period when “Earth and Mars, in their eternal march around the Sun, are obscured from each other by the fiery orb of the Sun itself. Like dancers on either side of a huge bonfire, the two planets are temporarily invisible to each other (great quote from our friends over at NASA).”

In other words, the presence of the Sun blocks or severely degrades the quality of radio signals passing between ground stations on Earth and spacecraft orbiting, or on, Mars.

Bits can be lost, packets can be dropped and even if signals do get through, and the data bitrates, typically running at hundreds of Kbps up to 2 MB/sec, when TGO communicates with ESA’s New Norcia or Malargüe ground stations, drop to just a few tens of bits per second (a typical home or mobile phone Internet connection is many times faster than this).

During the height of conjunction, it’s difficult to reliably send routine commands to a spacecraft at Mars (for ESA, these comprise TGO and Mars Express; in future it will include the ExoMars 2020 Rover), and communication limitations already start several weeks before the main conjunction period and last until several weeks after.

Further, TGO aerobraking requires the flight control team at ESA’s ESOC mission control centre in Darmstadt, Germany, to send commands and downlink telemetry more or less every day.

“During aerobraking we also need to be able to update our guidance commanding every day due to the unpredictability of the orbit following an aerobraking drag pass,” says Peter.

“So any uncertainty in communication reliability means that aerobraking has to be put on hold.”

This period occurs once every two years, and lasts about two weeks – in this case, 18 July until 4 August – at its peak.

Software gets updated

If waiting out conjunction season was the only consideration, aerobraking could have resumed as soon as mid-August, when communications once again became reliable.

“We decided to use the end of conjunction season as an opportunity to conduct a software upgrade for TGO, which had been in planning since after we initiated the campaign in March this year,” says Peter.

Spacecraft Operations Manager Peter Schmitz gives the thumbs up in the main control room at ESA’s control centre in Darmstadt, Germany, on 19 October 2016, shortly after the ExoMars Trace Gas Orbiter arrived at the Red Planet. Credit: ESA/J. Mai

The operating system improvements take into account lessons learned and glitches identified since the start of aerobraking and ensure that the spacecraft is optimised for the remaining campaign period, when the orbit will become even lower. (Some of the concomitant spacecraft operations challenges will include the orbital period falling to about 2 hours, and communication windows being severely reduced, to only 30-40 min per orbit.)

The new software also updates autonomous reactions in case the star trackers get blinded, ensures safe uplink of recovery command files, tunes monitoring thresholds used for failure detection and improves several recovery actions for several failure scenarios; overall, it will improve general robustness against failures during aerobraking

While your laptop or tablet at home routinely downloads and installs updates to its operating system software with little more than a brief notice not to unplug the device and please wait for a few minutes, upgrading TGO orbiting Mars at some 390 million km is another challenge entirely.

“We uploaded the new software starting on 14 August, sending the new code in four separate batches totalling 3 MB,” says Spacecraft Operations Engineer Johannes Bauer.

In total, it was a three week process to upload the software code, install it on one of the two processor modules, reboot with the new software and then install it on the other processor module.

“We had already been working for some time with our colleagues at Thales Alenia Space to test the new software and prepare for the upgrade, and worked intensively in the week preceding the 21st to get ready.”

The upload took some time, due to the aforementioned low bitrates and due to the necessity to check and verify that the uploaded software was completely and correctly received on board.

The new software was stored on board the back-up memory, and booted into operation, and once verified, the software was uploaded a second time for storage on the redundant memory.

“The spacecraft is now working as expected,” says Johannes.

Walking in all over again

With the update complete, the team are now preparing for the ‘walk-in phase’ to restart aerobraking.

This comprises a series of nine manoeuvres to lower the craft step-wise until it starts ‘feeling’ atmospheric drag, indicating that aerobraking is again underway, and is similar to what was conducted in March this year when the aerobraking campaign initially commenced.

The first manoeuvre – the biggest of the nine with a planned ‘delta-v’ (change in speed) of 5.3 m/sec – is planned for Wednesday, 30 August, at about 07:53 CEST, and will bring the craft down to 140 km altitude at pericentre passage.

The remaining eight manoeuvres will be much smaller, typically running at 0.8 to, later, 0.2 m/sec and occurring every two to four days, and lowering the altitude at pericentre passage by tens and then later just two or three km per burn.

“The target altitude at pericentre passage to restart aerobraking is around 110/115 km on 19 September, but this will depend on actual results and the Martian atmosphere,” says Johannes.

The flight dynamics teams at ESOC will be extremely busy during this period, conducting orbit determinations immediately after each burn to assess the performance and confirm the subsequent manoeuvre plan, all on a very tight schedule.

“It’s taken a lot of effort from the entire flight control team together with excellent support from our colleagues in flight dynamics, the ground stations and data systems, and we’re looking forward to restarting aerobraking,” says Operations Manager Schmitz.

“It means we’ll be that much closer to our final routine orbit and the start of science observations, the ultimate reason why we fly to Mars.”

---

Editor’s note:

During the software upgrades on 21 August, there was a gap in ground station coverage between the ESA deep-space stations in Argentina and Australia lasting about an hour. While not absolutely critical, it was highly desirable to maintain a link with TGO to monitor progress of the software installation and computer reset/reboot taking place on board.

64m antenna Kalyazin Credit: ESA

Due to advantageous geography, the Russian 64 m-diameter antenna at Kalyazin, in the Tver region some 300 km north of Moscow, could step in and provide telemetry downlink between 12:00 and 13:00 Moscow time (11:00- 12:00 CEST; 09:00-10:00 UTC). The reception was successful, and the information was transmitted in real time to ESOC for analysis.

See: Big dishes band together

 

 

 

 

from Rocket Science http://ift.tt/2xC7Y7S
v

2017 SkS Weekly Climate Change & Global Warming News Roundup #34

A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week. 

Editor's Pick

Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns 

 

Harvesting rice in Viet Nam. Global rice consumption trends are rising. Photo: FAO/Hoang Dinh Nam

With global warming expected to significantly impact future yields in countries located closer to the equator, the United Nations agriculture agency is calling on Asia-Pacific economies to take a leading role in adaptation and mitigation.

“Many APEC [Asia-Pacific Economic Cooperation] economies have already felt the full force of agricultural losses from natural disasters in recent years, with the vast majority of these being climate related,” said Kundhavi Kadiresan, Assistant Director-General and FAO Regional Representative for Asia and the Pacific.

Geographically, the negative impact of climate change on agricultural output could result in lower yields of rice, wheat, corn and soybeans in countries with tropical climates, compared with the impacts experienced by those in higher latitudes. Fisheries could also be affected by changes to water temperature, warned the Food and Agriculture Organization (FAO) today.

“The annual tally runs into the billions and billions of dollars in losses. So, the time to act is now. Policy makers need to prepare for changes in supply, shifting trade patterns and a need for greater investment in agriculture, fisheries, land and water management, that will benefit smallholder farmers and others that produce our food,” Mr. Kadiresan added.

Many vital agricultural regions in Asia are at risk of crossing key climate thresholds that would cause plant and animal productivity to decline, according to a meeting in Viet Nam of Agriculture Ministers of APEC member economies.

Based on the findings of the global research community, the International Panel on Climate Change (IPCC) anticipates that these trends are expected to worsen in the future with the projected impacts of anthropogenic climate change.

Much can be done to increase the efficiency of agriculture and land-use activities in Asia, according to Mr. Kadiresan. 

Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns, UN News Center, Aug 25, 2017

---

Links posted on Facebook

Sun Aug 20, 2017

• Curbing climate change: Why it’s so hard to act in time by Timothy H. Dixon, The Conversation US, Aug 17, 2017
• What should you say to a climate change skeptic? by Mira Abed, Los Angeles, Aug 18, 2017
• Researcher finds new evidence of western forest decline by Daniel Grossman, Yale Climate Connections, Aug 17, 2017
• The Trump administration just disbanded a federal advisory committee on climate change by Juliet Eilperin, Energy & Environment, Washington Post, Aug 20, 2017
• Let Monday’s eclipse be a call to action on climate change, Opinion by Rabbi Dan Fink, Idaho Statesman, Aug 18, 2017
• Britain’s seabird colonies face catastrophe as warming waters disrupt their food supply by Robin McKie, Observer/Guardian, Aug 19, 2017
• This Q&A Is Top Secret, Contains Leaked Info and Definitely Was Not Peer Reviewed by Theresa Riley, Moyers & Company, Aug 18, 2017
• Climate advisory group died quietly by Michael Doyle & Brittany Patterson, ClimateWire, Aug 17, 2017

Mon Aug 21, 2017

• Volkswagen To Bring Back The Iconic Microbus In 2022 — Only This Time It's Electric by Joann Muller, Forbes, Aug 19, 2017
• Q&A: The return of UK fracking and what it could mean for the climate by Jocelyn Timperley, Carbon Brief, Aug 16, 2017
• Arctic voyage notes global warming’s impact on ice, animals by Frank Jordan, AP/Fairbanks Daily News Miner, Aug 20, 2017
• What Happens to Solar Power in an Eclipse? We’ll Find Out Monday by Brad Pulmer, Climate, New York Times, Aug 18, 2017
• Greenland: how rapid climate change on world’s largest island will affect us all by Kathryn Adamson, The Conversation UK, Aug 18, 2017
• The Fundamentalists Holding Us Back from a Climate Change Solution by Allie Conti, Vice, Aug 20, 2017
• How Deeply Will Rising Temperatures Cut into Crop Yields? by Georgina Gustin, InsideClimate News, Aug 21, 2017
• Are the floating houses of the Netherlands a solution against the rising seas? by Olga Mecking, Pacific Standard, Aug 21, 2017

Tue Aug 22, 2017

• Climate Change May Shrink the World’s Fish by Graig Welch, National Geographic, Aug 21, 2017
• How Climate Change Canceled the Grizzly Salmon Run by Ed Young, The Atlantic, Aug 21, 2017
• Climate Change Solutions: Bringing Forests to Center Stage by Nancy Harris & Donna Lee, World Resources Instittue, Aug 21, 2017
• A controversial California effort to fight climate change just got some good news by Chelsea Harvey, Energy & Environment, Washington Post, Aug 21, 2017
• California power grid survives solar eclipse unscathed by David R Baker, SF Gate, Aug 21, 2017
• Agriculture a culprit in global warming, says U.S. research by Ellen Wulfhorst, Thomson Reuters Foundation, Aug 22, 2017
• People Furthest Apart on Climate Views Are Often the Most Educated by Umair Irfan, ClimateWire/Scientific American, Aug 22, 2017
• Can Anyone, Even Walmart, Stem The Heat-Trapping Flood Of Nitrogen On Farms? by Dan Charles, NPR News, Aug 21, 2017

Wed Aug 23, 2017

• Doctors must respond to changes in the politics of climate change by Gary W Yohe & Kristie L Ebi, Stat, Aug 22, 2017
• Will the U.S. Ever Build Another Big Coal Plant? by Benjamin Storrow, ClimateWire/Scientific American, Aug 21, 2017
• The World Eyes Yet Another Unconventional Source of Fossil Fuels by Nicola Jones, Yale Environment 360, Aug 21, 2017
• Alaska’s Permafrost Is Thawing by Henry Fountain, New York Times, Aug 23, 2017
• Harvard scientists took Exxon’s challenge; found it using the tobacco playbook by Dana Nuccitelli, Climate Consensus - the 97%, Guardian, Aug 23, 2017
• The Surprising Effect of Ocean Waves on Global Climate by Tim Lougheed, Ensia, Aug 22, 2017
• Tropical Depression Harvey an Extremely Dangerous Flood Threat for Texas, Louisiana; Hurricane, Storm Surge Watches Issued by Jon Erdman, Weather Underground, Aug 23, 2017
• Why is climate change’s 2 degrees Celsius of warming limit so important? by David Titley, The Conversation US, Aug 22, 2017

Thu Aug 24, 2017

• In Italy’s Drought-Hit Vineyards, the Harvest of a Changing Climate by Jason Horowitz, New York Times, Aug 22, 2017
• The Fight Against Climate Change Could Get Unexpected Help from Seaweed by Dom Galeon, Futurism, Aug 23, 2017
• Another US agency deletes references to climate change on government website by Jamiles Lartey, Guardian, Aug 23, 2017
• Tropical Storm Harvey projected to become 'major hurricane' by Nicole Chavez, CNN, Aug 24, 2017
• Trump keeps saying ‘clean coal.’ It does not mean what he thinks it means. by Dino Gandino, Energy & Environment, Washington Post, Aug 23, 2017
• Typhoon Hato, a maximum category 10 storm, slams into Hong Kong, Macau, AAP/New Zealand Herald, Aug 23, 2017
• Coal in decline: an energy industry on life support by Adam Morton, Guardian, Aug 23, 2017
• Nine states aggressively step up plans to cut emissions by David Abel, Boston Globe, Aug 23, 2017

Fri Aug 25, 2017

• How machine learning could help to improve climate forecasts by Nicola Jones, Nature, Aug 23, 2017
• Can we save our lakes from global warming? by Bob Berwyn, Deutsche Welle, Aug 23, 2017
• New study finds that climate change costs will hit Trump country hardest by John Abraham, Climate Consensus - the 97%, Guardian, Aug 24, 2017
• Hurricane Harvey Is Going to Slam Into Texas and the National Flood Insurance Program Is a Mess by Nathalie Baptiste, Climate Desk/Mother Jones, Aug 25, 2017
• Harvey’s intensity and rainfall potential tied to global warming by Brendan Gibbons, San Antonio Express-News, Aug 25, 2017
• Thirsty world must wake up to looming water crisis, expert says by Megan Rowling, Thomson Reuters Foundation, Aug 24, 2017
• I was an Exxon-funded climate scientist by Katharine Hayhoe, The Conversation US, Aug 24, 2017
• What you can and can’t say about climate change and Hurricane Harvey by Chris Mooney, Energy & Environment, Washington Post, Aug 25, 2017

Sat Aug 26, 2017

• Failure to Set Cost of Carbon Hampers Trump’s Effort to Expand Use of Fossil Fuels by Andrew Revkin, ProPublica, Aug 24, 2017
• We’ve been underestimating the solar industry’s momentum. That could be a big problem by Chelsea Harvey, Energy & Environment, Washington Post, Aug 25, 2017
• Worst monsoon floods in years kill more than 1,200 across South Asia by Jatindra Dash & Ruma Paul, Reuters, Aug 25, 2017
• Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns, UN News Center, Aug 25, 2017
• Russian tanker sails through Arctic without icebreaker for first time by Patrick Barkham, Guardian, Aug 24, 2017
• Climate Change Is Making This Bolivian Village a Ghost Town by Ben Walker, InsideClimate News, Aug 25, 2017

from Skeptical Science http://ift.tt/2xlyyCQ

A chronological listing of news articles posted on the Skeptical Science Facebook page during the past week. 

Editor's Pick

Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns 

 

Harvesting rice in Viet Nam. Global rice consumption trends are rising. Photo: FAO/Hoang Dinh Nam

With global warming expected to significantly impact future yields in countries located closer to the equator, the United Nations agriculture agency is calling on Asia-Pacific economies to take a leading role in adaptation and mitigation.

“Many APEC [Asia-Pacific Economic Cooperation] economies have already felt the full force of agricultural losses from natural disasters in recent years, with the vast majority of these being climate related,” said Kundhavi Kadiresan, Assistant Director-General and FAO Regional Representative for Asia and the Pacific.

Geographically, the negative impact of climate change on agricultural output could result in lower yields of rice, wheat, corn and soybeans in countries with tropical climates, compared with the impacts experienced by those in higher latitudes. Fisheries could also be affected by changes to water temperature, warned the Food and Agriculture Organization (FAO) today.

“The annual tally runs into the billions and billions of dollars in losses. So, the time to act is now. Policy makers need to prepare for changes in supply, shifting trade patterns and a need for greater investment in agriculture, fisheries, land and water management, that will benefit smallholder farmers and others that produce our food,” Mr. Kadiresan added.

Many vital agricultural regions in Asia are at risk of crossing key climate thresholds that would cause plant and animal productivity to decline, according to a meeting in Viet Nam of Agriculture Ministers of APEC member economies.

Based on the findings of the global research community, the International Panel on Climate Change (IPCC) anticipates that these trends are expected to worsen in the future with the projected impacts of anthropogenic climate change.

Much can be done to increase the efficiency of agriculture and land-use activities in Asia, according to Mr. Kadiresan. 

Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns, UN News Center, Aug 25, 2017

---

Links posted on Facebook

Sun Aug 20, 2017

• Curbing climate change: Why it’s so hard to act in time by Timothy H. Dixon, The Conversation US, Aug 17, 2017
• What should you say to a climate change skeptic? by Mira Abed, Los Angeles, Aug 18, 2017
• Researcher finds new evidence of western forest decline by Daniel Grossman, Yale Climate Connections, Aug 17, 2017
• The Trump administration just disbanded a federal advisory committee on climate change by Juliet Eilperin, Energy & Environment, Washington Post, Aug 20, 2017
• Let Monday’s eclipse be a call to action on climate change, Opinion by Rabbi Dan Fink, Idaho Statesman, Aug 18, 2017
• Britain’s seabird colonies face catastrophe as warming waters disrupt their food supply by Robin McKie, Observer/Guardian, Aug 19, 2017
• This Q&A Is Top Secret, Contains Leaked Info and Definitely Was Not Peer Reviewed by Theresa Riley, Moyers & Company, Aug 18, 2017
• Climate advisory group died quietly by Michael Doyle & Brittany Patterson, ClimateWire, Aug 17, 2017

Mon Aug 21, 2017

• Volkswagen To Bring Back The Iconic Microbus In 2022 — Only This Time It's Electric by Joann Muller, Forbes, Aug 19, 2017
• Q&A: The return of UK fracking and what it could mean for the climate by Jocelyn Timperley, Carbon Brief, Aug 16, 2017
• Arctic voyage notes global warming’s impact on ice, animals by Frank Jordan, AP/Fairbanks Daily News Miner, Aug 20, 2017
• What Happens to Solar Power in an Eclipse? We’ll Find Out Monday by Brad Pulmer, Climate, New York Times, Aug 18, 2017
• Greenland: how rapid climate change on world’s largest island will affect us all by Kathryn Adamson, The Conversation UK, Aug 18, 2017
• The Fundamentalists Holding Us Back from a Climate Change Solution by Allie Conti, Vice, Aug 20, 2017
• How Deeply Will Rising Temperatures Cut into Crop Yields? by Georgina Gustin, InsideClimate News, Aug 21, 2017
• Are the floating houses of the Netherlands a solution against the rising seas? by Olga Mecking, Pacific Standard, Aug 21, 2017

Tue Aug 22, 2017

• Climate Change May Shrink the World’s Fish by Graig Welch, National Geographic, Aug 21, 2017
• How Climate Change Canceled the Grizzly Salmon Run by Ed Young, The Atlantic, Aug 21, 2017
• Climate Change Solutions: Bringing Forests to Center Stage by Nancy Harris & Donna Lee, World Resources Instittue, Aug 21, 2017
• A controversial California effort to fight climate change just got some good news by Chelsea Harvey, Energy & Environment, Washington Post, Aug 21, 2017
• California power grid survives solar eclipse unscathed by David R Baker, SF Gate, Aug 21, 2017
• Agriculture a culprit in global warming, says U.S. research by Ellen Wulfhorst, Thomson Reuters Foundation, Aug 22, 2017
• People Furthest Apart on Climate Views Are Often the Most Educated by Umair Irfan, ClimateWire/Scientific American, Aug 22, 2017
• Can Anyone, Even Walmart, Stem The Heat-Trapping Flood Of Nitrogen On Farms? by Dan Charles, NPR News, Aug 21, 2017

Wed Aug 23, 2017

• Doctors must respond to changes in the politics of climate change by Gary W Yohe & Kristie L Ebi, Stat, Aug 22, 2017
• Will the U.S. Ever Build Another Big Coal Plant? by Benjamin Storrow, ClimateWire/Scientific American, Aug 21, 2017
• The World Eyes Yet Another Unconventional Source of Fossil Fuels by Nicola Jones, Yale Environment 360, Aug 21, 2017
• Alaska’s Permafrost Is Thawing by Henry Fountain, New York Times, Aug 23, 2017
• Harvard scientists took Exxon’s challenge; found it using the tobacco playbook by Dana Nuccitelli, Climate Consensus - the 97%, Guardian, Aug 23, 2017
• The Surprising Effect of Ocean Waves on Global Climate by Tim Lougheed, Ensia, Aug 22, 2017
• Tropical Depression Harvey an Extremely Dangerous Flood Threat for Texas, Louisiana; Hurricane, Storm Surge Watches Issued by Jon Erdman, Weather Underground, Aug 23, 2017
• Why is climate change’s 2 degrees Celsius of warming limit so important? by David Titley, The Conversation US, Aug 22, 2017

Thu Aug 24, 2017

• In Italy’s Drought-Hit Vineyards, the Harvest of a Changing Climate by Jason Horowitz, New York Times, Aug 22, 2017
• The Fight Against Climate Change Could Get Unexpected Help from Seaweed by Dom Galeon, Futurism, Aug 23, 2017
• Another US agency deletes references to climate change on government website by Jamiles Lartey, Guardian, Aug 23, 2017
• Tropical Storm Harvey projected to become 'major hurricane' by Nicole Chavez, CNN, Aug 24, 2017
• Trump keeps saying ‘clean coal.’ It does not mean what he thinks it means. by Dino Gandino, Energy & Environment, Washington Post, Aug 23, 2017
• Typhoon Hato, a maximum category 10 storm, slams into Hong Kong, Macau, AAP/New Zealand Herald, Aug 23, 2017
• Coal in decline: an energy industry on life support by Adam Morton, Guardian, Aug 23, 2017
• Nine states aggressively step up plans to cut emissions by David Abel, Boston Globe, Aug 23, 2017

Fri Aug 25, 2017

• How machine learning could help to improve climate forecasts by Nicola Jones, Nature, Aug 23, 2017
• Can we save our lakes from global warming? by Bob Berwyn, Deutsche Welle, Aug 23, 2017
• New study finds that climate change costs will hit Trump country hardest by John Abraham, Climate Consensus - the 97%, Guardian, Aug 24, 2017
• Hurricane Harvey Is Going to Slam Into Texas and the National Flood Insurance Program Is a Mess by Nathalie Baptiste, Climate Desk/Mother Jones, Aug 25, 2017
• Harvey’s intensity and rainfall potential tied to global warming by Brendan Gibbons, San Antonio Express-News, Aug 25, 2017
• Thirsty world must wake up to looming water crisis, expert says by Megan Rowling, Thomson Reuters Foundation, Aug 24, 2017
• I was an Exxon-funded climate scientist by Katharine Hayhoe, The Conversation US, Aug 24, 2017
• What you can and can’t say about climate change and Hurricane Harvey by Chris Mooney, Energy & Environment, Washington Post, Aug 25, 2017

Sat Aug 26, 2017

• Failure to Set Cost of Carbon Hampers Trump’s Effort to Expand Use of Fossil Fuels by Andrew Revkin, ProPublica, Aug 24, 2017
• We’ve been underestimating the solar industry’s momentum. That could be a big problem by Chelsea Harvey, Energy & Environment, Washington Post, Aug 25, 2017
• Worst monsoon floods in years kill more than 1,200 across South Asia by Jatindra Dash & Ruma Paul, Reuters, Aug 25, 2017
• Climate change threatens agricultural trade in Pacific Rim economies, UN agency warns, UN News Center, Aug 25, 2017
• Russian tanker sails through Arctic without icebreaker for first time by Patrick Barkham, Guardian, Aug 24, 2017
• Climate Change Is Making This Bolivian Village a Ghost Town by Ben Walker, InsideClimate News, Aug 25, 2017

from Skeptical Science http://ift.tt/2xlyyCQ

Confused sunflowers during eclipse

Photo taken during the August 21, 2017 solar eclipse by Sarah Chisholm Photography. She calls this photo “Hazed and Confused.”

Sarah Chisholm wrote:

Here are some seriously confused sunflowers during the maximum solar eclipse (about 70% here in Ontario) yesterday. I drove by the field of them when the eclipse was just beginning to be noticeable, and there they were, every last bloom upright and pointed in the same direction, not a single sunflower head turned askew. I decided to swing into town for a cold drink at a drive-thru (was it ever HOT yesterday!) while I waited for the darkness of the celestial phenomenon to deepen. When I got back to the sunflowers, the sun was almost fully eclipsed, and did I ever giggle – the heads were turned in all directions, some right around 180 degrees from where they’d been less than a half hour before! Others had just given up and flopped right over, and still some were intently ‘watching’ the eclipse. You could tell they were twitchy because they would ‘shudder’ just on the edge of your vision, never quite letting you see them move.

They were confused about the change in light!

Thank you, Sarah!

By the way, the process by which sunflowers and other plants track the motion of the sun across the sky is called solar tracking or heliotropism. Read more about it here.

Bottom line: Sunflowers during the August 21, 2017 solar eclipse, not sure which way to turn!

from EarthSky http://ift.tt/2wPW5he

Photo taken during the August 21, 2017 solar eclipse by Sarah Chisholm Photography. She calls this photo “Hazed and Confused.”

Sarah Chisholm wrote:

Here are some seriously confused sunflowers during the maximum solar eclipse (about 70% here in Ontario) yesterday. I drove by the field of them when the eclipse was just beginning to be noticeable, and there they were, every last bloom upright and pointed in the same direction, not a single sunflower head turned askew. I decided to swing into town for a cold drink at a drive-thru (was it ever HOT yesterday!) while I waited for the darkness of the celestial phenomenon to deepen. When I got back to the sunflowers, the sun was almost fully eclipsed, and did I ever giggle – the heads were turned in all directions, some right around 180 degrees from where they’d been less than a half hour before! Others had just given up and flopped right over, and still some were intently ‘watching’ the eclipse. You could tell they were twitchy because they would ‘shudder’ just on the edge of your vision, never quite letting you see them move.

They were confused about the change in light!

Thank you, Sarah!

By the way, the process by which sunflowers and other plants track the motion of the sun across the sky is called solar tracking or heliotropism. Read more about it here.

Bottom line: Sunflowers during the August 21, 2017 solar eclipse, not sure which way to turn!

from EarthSky http://ift.tt/2wPW5he