In the early morning hours on Wednesday, we have a chance to see bright streaks across the sky, thanks to Halley’s Comet and the eta Aquariid meteor shower.
Comet Halley is probably the most well-known comet in the world. It puts on a spectacular show every time it flies past our planet, but it only does so once every 75 years.
Twice each year, though, we get a reminder from 1P/Halley that it’s only a matter of time before it comes back for another pass. The first such reminder arrives in the first week of May, in the form of bright streaks of light across the night sky.
This is the eta Aquariid meteor shower, which peaks on the night of May 5-6.
The radiant of the eta Aquariid meteor shower, in the hours before dawn, on May 6. Look for a lineup of Jupiter, Saturn and Mars, as well. Credit: Stellarium/Scott Sutherland
It’s at this time of the year when Earth is making its first pass through the trail of dust and ice left behind by 1P/Halley, as it swings through the inner solar system and around the Sun. The peak of the meteor shower, typically seen in the morning hours of May 6, is when we cross the densest part of that stream. The planet makes a second pass through Halley’s debris trail in late October, producing the Orionids meteor shower at that time.
WILL WE SEE IT?
The best time to see the eta Aquariids is in the few hours just before dawn on May 6. The radiant – the point in the sky where the meteors appear to originate from – only rises above the eastern horizon at around 3 a.m., local time.
This year is not ideal for the eta Aquariids, due to how soon dawn arrives after the radiant rises, and due to the presence of a nearly Full Moon in the sky. Fortunately, with the Moon in the southwestern part of the sky as the radiant rises in the east, its bright light will not be directly in a viewer’s eyes. The light it does cast will ‘wash out’ the dimmest meteors from the shower, though.
Sky conditions will also be an important factor. Check your cloud forecast for the early morning, to see if your skies will be clear enough.
If it is cloudy where you are, thus blocking your view of the meteor shower, there are other ways to check it out.
Astronomy Live Stream also presents nightly views of the sky over Colorado.
WHAT CAN WE SEE?
The eta Aquariids typically produce around 50 meteors per hour under ideal conditions (clear, dark sky, with the meteor shower radiant directly overhead). Most observers will likely see about half that number, so around 20-25 per hour, under this year’s conditions.
The flash of a meteor is the result of one of those bits of dust or ice from the comet debris trail hitting the top of Earth’s atmosphere.
A primer on meteoroids, meteors and meteorites. Credits: Scott Sutherland/NASA JPL (Asteroids Ida & Dactyl)/NASA Earth Observatory (Blue Marble)
When a typical ‘meteoroid’ hits the top of the atmosphere, it is travelling around a hundred thousand kilometres per hour. It very quickly compresses the air in its path, so much so that the air heats up to glow, white-hot! This glowing is the ‘meteor’ that we see streaking through the air, high above the ground.
All the while, the air is pressing back on the meteoroid, causing it to slow down, and sometimes exerting enough force on the meteoroid to shatter it! Once the meteoroid slows to the point where it can no longer heat the air to the point of glowing, the meteor winks out.
This eta Aquariids meteor shower does not tend to produce bright fireballs, as the Lyrids do. The meteoroids are moving so quickly when they hit our atmosphere, however, that they can produce a phenomenon called persistent trains.
Watch below to see a persistent train from the Geminid meteor shower
When a typical cometary meteoroid hits the top of Earth’s atmosphere, it is moving fast enough to produce a meteor flash (as mentioned above). The particles in the eta Aquariid stream, however, hit Earth’s atmosphere travelling at nearly two and a half times faster than average!
Streaking through the air at 240,000 km/h, meteoroids from Comet Halley produce the usual brief meteor flash. They can also result in a bonus. Once the meteor goes out, a glowing trail is left behind, floating in the air, called a persistent train. Some persistent trains last for minutes after the meteor flash, while others remain visible for hours.
Since persistent trains have only rarely been recorded, scientists still aren’t quite sure what causes them. Two basic ideas could explain them, though.
The first is that the meteoroids are travelling fast enough to strip electrons from the air molecules, leaving them in an ionized state. As the air molecules snatch up electrons from their surroundings, they release energy in the form of light. Since this process can take much longer than the original meteor flash, the ‘train’ appears fainter, and it can persist for some time after the meteor flash ends.
The other idea involves what is known as ‘chemiluminescence’. Metals vaporizing off the surface of the fast-moving meteoroids can chemically react with ozone and oxygen in the air, to produce a glow.
One of these explanations may account for these ‘trains’, or both may cover different occurrences, at different times, and even between individual meteors. It will take more sightings of these to explain them fully.
WATCH BELOW: METEORS SPOTTED FROM THE INTERNATIONAL SPACE STATION
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)
Alberta family searches for answers in teen's sudden death after COVID exposure, negative tests – CBC.ca
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.
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.
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.”
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.)