Connect with us


Stalking Starlink's 'DarkSat' – Universe Today



By now, you’ve no doubt heard of (or seen) Starlink. SpaceX’s mega-satellite constellation has become a permanent fixture in our skies as of late, with several routine passes on any given week. But have you seen the supposed ‘black sheep’ of the flock, DarkSat?

Starlink is looking to provide global internet access with latency (lag time) of 25/35 milliseconds, with connectivity speeds comparable to existing cable and fiber optic with services starting in late 2020. SpaceX recently announced that Starlink users will connect with the service via a ‘UFO on a Stick‘ antenna. (no kidding!)

Thus far, SpaceX has launched 182 Starlink satellites in three batches (that’s three times sixty, plus two early test satellites), and by the end of 2020, SpaceX will add nearly 1600 more satellites. SpaceX filed for 12,000 satellites to fill out the initial constellation, and there may ultimately be 42,000 Starlink satellites in low Earth orbit.

The first two Starlink test satellites set for launch. Credit: SpaceX

Each Starlink satellite is about the size of a table, and are flat-packed IKEA-style in the Falcon-9 nose fairing. Each satellite also sports a large solar panel that’s unfurled once they reach orbit.

60 Starlink satellites, stacked in a nose fairing for launch. Credit: SpaceX

Those numbers are also set to increase today, with the launch of Starlink 3 (batch number four) from Cape Canaveral Air Force station at 14:49 Universal Time (UT)/9:49 AM Eastern Standard Time (EST). SpaceX is now already the largest operator of satellites in low Earth orbit, and plans to reach a cadence of two Starlink launches a month, or one every two weeks.

The reality of ‘mega-satellite constellations’ such as Starlink in 2020 has also alarmed the astronomical community and generated controversy. Will artificial stars soon out number real ones in the night sky? This also comes as projects such as the Large Synoptic Survey Telescope (LSST) are set to come online in the coming years.

Starlink satellites trail through the field of view of the Dark Energy Camera. Credit: DELVE Survey/CTIO/AURA/NSF

The Rise of DarkSat

SpaceX made an
effort to address the issue during the November launch, and stated
that they painted one of the new Starlink satellites black in an
effort to reduce reflectivity. To date, SpaceX has not released
images of just what ‘DarkSat’ looks like up close. Several US
classified satellites such as Lacrosse 5 typically pull a ‘vanishing
act’ and are suspected of using some sort of stealth technology,
though of course, the U.S. Department of Defense isn’t sharing this
ability with SpaceX.

It took a while for
the identity of the rumored DarkSat to become general knowledge.
Typically, objects are cataloged by U.S. Combined Space Operations
Center (CSpOC) Space-Track shortly after launch, but the flood of new
objects generated by a typical Starlink launch poses a unique
challenge. The third batch launch (dubbed Starlink 2) that included
DarkSat put 60 objects in orbit.

T.S. Kelso over at Celestrak later identified DarkSat as NORAD ID 2020-001U (COSPAR ID 44932).

[embedded content]

A discussion panel at the recent 235th meeting of the American Astronomical Society addressed the Starlink issue. “The LSST survey is the most impacted by bright satellite trails because of its wide-fast-deep coverage of the sky,” Says Patrick Seitzer (University of Michigan) during the AAS panel on Starlink. “Original Starlinks will saturate detectors.” LSST is set to see first light in 2022.

Starlink with star trails over Virginia. Image credit and copyright: Chris Becke (@BeckePhysics)

The Starlink
satellites are also much more visible during original deployment than
when they reach operational orbits higher up. For comparison, the
original Iridium satellites were placed in an operational orbit 781
kilometers (485 miles) up, and where only visible to the naked eye
when they flared. The Starlink mega-constellation will deploy in
three orbital shells with operational altitudes of 340 kilometers
(210 miles), 550 kilometers (340 miles) and 1,150 kilometers (710
miles) respectively. As of writing this, DarkSat 2020-001U’s orbit
is still on the low end, at 366 by 368 kilometers. DarkSat should
reach operation altitude and orientation by the end of February 2020.

Like the Iridium
satellites, Starlink will also have an impact on the radio astronomy
end of the spectrum as well, something that’ll need to be

What Observers are Seeing

Want to track Starlink and DarkSat for yourself? – All of the Starlink payloads are up on Heavens-Above on both the App and the website… this great utility is probably the easiest way to catch a Starlink pass. If you have the site configured for your location, simply look for a string of dawn or dusk passes, and watch the region of the sky noted during the given time. Note that the brightness of the Starlink satellite train seems to be heavily dependent on the viewing geometry: for example, we’ve seen lots of bright flaring flashes well into the negative magnitudes as the train passes the same spot in the sky when a pass is around 45 degrees in elevation opposite to the Sun, while the train seems to have the same steady brightness when passing directly overhead near the zenith. When the satellites are lower towards the horizon in the sunward direction, however, they are considerably fainter, and only visible with binoculars.

DarkSat ‘U’ compared to other Starlink satellites and bright stars. Credit and copyright: Thierry Legault.

“For the moment, nothing looks different between Darksat and the others,” veteran astrophotographer Thierry Legault told Universe Today. “When I filmed them, the units of the last launch were brighter than magnitude +2, that’s very bright!!!”

[embedded content]

If Starlink-3
launches on schedule Monday, we can expect a deployment of the next
60 satellites in a ‘string of pearls’ configuration about an hour
later. Using orbital TLEs provided by Dr. Marco Langbroek, we see
good dusk passes Monday night centered on:

Paris: 16:45 UT

Norfolk: 22:45 UT

St. Louis: 00:20 UT
(on January 28th).

Los Angeles: 1:54 UT (on January 28th).

Raining satellites: Starlink passes behind a tree, with star trails. Image credit and copyright: Marco Langbroek.

We managed to catch
a recent Starlink pass at dawn of the second batch launched in
November 2019 from here in Norfolk, Virginia as a set of two dozen
satellites equally spaced about five degrees apart caught the Sun’s
first rays passing out of the Earth’s shadow. They were also easily
visible to the naked eye, about as bright as the stars in the Big
Dipper asterism at magnitude +2.

Expect fielding an uptick in spurious UFO sightings versus Starlink as well. This is already happening, along with anomalous ‘mystery drone’ sightings out in the western U.S. OneWeb also plans to join the mega-satellite constellation game in 2020, with the launch of their first operational batch of 34 satellites from the Baikonur Cosmodrome in early February 2020. Based on the first test batch of six OneWeb satellites launched in February 2019 these satellites are much fainter at +8th magnitude, though these will still show up on deep sky images.

It’s strange that this is our new reality. Controversy notwithstanding, Starlink seems set to be a modern reality for the night sky, and backyard satellite trackers are playing a crucial role in documenting exactly what they are seeing as the modern mega-constellations unfurl overhead.

Follow us (@Astroguyz) on Twitter for latest updates on how to see the latest Starlink-4 satellite train in orbit.

Let’s block ads! (Why?)

Source link

Continue Reading


New species of crested dinosaur identified in Mexico



A team of palaeontologists in Mexico have identified a new species of dinosaur after finding its 72 million-year-old fossilized remains almost a decade ago, Mexico’s National Institute of Anthropology and History (INAH) said on Thursday.

The new species, named Tlatolophus galorum, was identified as a crested dinosaur after 80% of its skull was recovered, allowing experts to compare it to other dinosaurs of that type, INAH said.

The investigation, which also included specialists from the National Autonomous University of Mexico, began in 2013 with the discovery of an articulated tail in the north-central Mexican state of Coahuila, where other discoveries have been made.

“Once we recovered the tail, we continued digging below where it was located. The surprise was that we began to find bones such as the femur, the scapula and other elements,” said Alejandro Ramírez, a scientist involved in the discovery.

Later, the scientists were able to collect, clean and analyze other bone fragments from the front part of the dinosaur’s body.

The palaeontologists had in their possession the crest of the dinosaur, which was 1.32 meters long, as well as other parts of the skull: lower and upper jaws, palate and even a part known as the neurocranium, where the brain was housed, INAH said.

The Mexican anthropology body also explained the meaning of the name – Tlatolophus galorum – for the new species of dinosaur.

Tlatolophus is a mixture of two words, putting together a term from the indigenous Mexican language of Nahuatl that means “word” with the Greek term meaning “crest”. Galorum refers to the people linked to the research, INAH said.


(Reporting by Abraham Gonzalez; Writing by Drazen Jorgic; Editing by Ana Nicolaci da Costa)

Continue Reading


Alberta family searches for answers in teen's sudden death after COVID exposure, negative tests –



A southern Alberta mother and father are grappling with the sudden, unexplained death of their 17-year-old daughter, and with few answers, they’re left wondering if she could be the province’s youngest victim of COVID-19.

Sarah Strate — a healthy, active Grade 12 student at Magrath High School who loved singing, dancing and being outdoors — died on Monday, less than a week after being notified she’d been exposed to COVID-19.

While two tests came back negative, her parents say other signs point to the coronavirus, and they’re waiting for more answers. 

“It was so fast. It’s all still such a shock,” said Sarah’s mother, Kristine Strate. “She never even coughed. She had a sore throat and her ears were sore for a while, and [she had] swollen neck glands.”

Kristine said Sarah developed mild symptoms shortly after her older sister — who later tested positive for COVID-19 —  visited from Lethbridge, one of Alberta’s current hot spots for the virus.

The family went into isolation at their home in Magrath on Tuesday, April 20. They were swabbed the next day and the results were negative.

‘Everything went south, super-fast’

By Friday night, Sarah had developed fever and chills. On Saturday, she started vomiting and Kristine, a public health nurse, tried to keep her hydrated.

“She woke up feeling a bit more off on Monday morning,” Kristine said. “And everything went south, super-fast.”

Sarah had grown very weak and her parents decided to call 911 when she appeared to become delirious.

“She had her blanket on and I was talking to her and, in an instant, she was unresponsive,” said Kristine, who immediately started performing CPR on her daughter.

When paramedics arrived 20 minutes later, they were able to restore a heartbeat and rushed Sarah to hospital in Lethbridge, where she died.

“I thought there was hope once we got her heart rate back. I really did,” recalled Sarah’s father, Ron.

“He was praying for a miracle, and sometimes miracles don’t come,” said Kristine.

Strate’s parents say her health deteriorated quickly after being exposed to COVID-19. She died at Chinook Regional Hospital in Lethbridge on Monday. (Ron Strate)

Searching for answers

At the hospital, the family was told Sarah’s lungs were severely infected and that she may have ended up with blood clots in both her heart and lungs, a condition that can be a complication of COVID-19.

But a second test at the hospital came back negative for COVID-19.

“There really is no other answer,” Ron said. “When a healthy 17-year-old girl, who was sitting up in her bed and was able to talk, and within 10 minutes is unconscious on our floor — there was no reason [for it].”

The province currently has no record of any Albertans under the age of 20 who have died of COVID-19.

According to the Strate family, the medical examiner is running additional blood and tissue tests, in an effort to uncover the cause of Sarah’s death.

‘Unusual but not impossible’

University of Alberta infectious disease specialist Dr. Lynora Saxinger, who was not involved in Sarah’s treatment, says it is conceivable that further testing could uncover evidence of a COVID-19 infection, despite two negative test results.

However, she hasn’t seen a similar case in Alberta.

“It would be unusual but not impossible because no test is perfect. We have had cases where an initial test is negative and then if you keep on thinking it’s COVID and you re-test, you then can find COVID,” she said.

According to Saxinger, the rate of false negatives is believed to be very low. But it can happen if there are problems with the testing or specimen collection.

She says people are more likely to test positive after symptoms develop. 

“The best sensitivity of the test is around day four or five of having symptoms,” she said. “So you can miss things if you test very, very early. And with new development of symptoms, it’s always a good time to re-test because then the likelihood of getting a positive test is a little higher. But again, no test is perfect.” 

Sarah deteriorated so quickly — dying five days after she first developed symptoms — she didn’t live long enough to make it to her follow-up COVID-19 test. Instead, it was done at the hospital.

‘An amazing kid’

The Strate family now faces an agonizing wait for answers — one that will likely take months — about what caused Sarah’s death.

But Ron, who teaches at the school where Sarah attended Grade 12, wants his daughter to be remembered for the life she lived, not her death.

Strate, pictured here at three years old, had plans to become a massage therapist. She attended Grade 12 at Magrath High School and was an active, healthy teenager who was involved in sports, music and the school’s suicide prevention group. (Ron Strate)

Sarah was one of five children. Ron says she was strong, active and vibrant and had plans to become a massage therapist after graduating from high school.

She played several sports and loved to sing and dance as part of a show choir. She was a leader in the school’s suicide prevention group and would stand up for other students who were facing bullying.

“She’s one of the leaders in our Hope Squad … which goes out and helps kids to not be scared,” he father said.

“She’s an amazing kid.”

Sarah would often spend hours helping struggling classmates, and her parents hope her kindness is not forgotten.

“She’d done so many good things. Honestly, I’ve got so many messages from parents saying, ‘You have no idea how much your daughter helped our kid,'” said Ron.

“This 17-year-old girl probably lived more of a life in 17 years than most adults will live in their whole lives. She was so special. I love her so much.”

Let’s block ads! (Why?)

Source link

Continue Reading


China launches key module of space station planned for 2022



BEIJING (Reuters) -China launched an unmanned module on Thursday containing what will become living quarters for three crew on a permanent space station that it plans to complete by the end of 2022, state media reported.

The module, named “Tianhe”, or “Harmony of the Heavens”, was launched on the Long March 5B, China’s largest carrier rocket, at 11:23 a.m. (0323 GMT) from the Wenchang Space Launch Centre on the southern island of Hainan.

Tianhe is one of three main components of what would be China’s first self-developed space station, rivalling the only other station in service – the International Space Station (ISS).

The ISS is backed by the United States, Russia, Europe, Japan and Canada. China was barred from participating by the United States.

“(Tianhe) is an important pilot project in the building of a powerful nation in both technology and in space,” state media quoted President Xi Jinping as saying in a congratulatory speech.

Tianhe forms the main living quarters for three crew members in the Chinese space station, which will have a life span of at least 10 years.

The Tianhe launch was the first of 11 missions needed to complete the space station, which will orbit Earth at an altitude of 340 to 450 km (211-280 miles).

In the later missions, China will launch the two other core modules, four manned spacecraft and four cargo spacecraft.

Work on the space station programme began a decade ago with the launch of a space lab Tiangong-1 in 2011, and later, Tiangong-2 in 2016.

Both helped China test the programme’s space rendezvous and docking capabilities.

China aims to become a major space power by 2030. It has ramped up its space programme with visits to the moon, the launch of an uncrewed probe to Mars and the construction of its own space station.

In contrast, the fate of the ageing ISS – in orbit for more than two decades – remains uncertain.

The project is set to expire in 2024, barring funding from its partners. Russia said this month that it would quit the project from 2025.

Russia is deepening ties with China in space as tensions with Washington rise.

Moscow has slammed the U.S.-led Artemis moon exploration programme and instead chosen to join Beijing in setting up a lunar research outpost in the coming years.

(Reporting by Ryan Woo and Liangping Gao; Editing by Christian Schmollinger, Simon Cameron-Moore and Lincoln Feast.)

Continue Reading