Science

Asteroid Apophis will visit Earth in 2029, and this European satellite will be along for the ride

Published

2 months ago

July 16, 2024

The European Space Agency is fast-tracking a new mission called Ramses, which will fly to near-Earth asteroid 99942 Apophis and join the space rock in 2029 when it comes very close to our planet — closer even than the region where geosynchronous satellites sit.

Ramses is short for Rapid Apophis Mission for Space Safety and, as its name suggests, is the next phase in humanity’s efforts to learn more about near-Earth asteroids (NEOs) and how we might deflect them should one ever be discovered on a collision course with planet Earth.

In order to launch in time to rendezvous with Apophis in February 2029, scientists at the European Space Agency have been given permission to start planning Ramses even before the multinational space agency officially adopts the mission. The sanctioning and appropriation of funding for the Ramses mission will hopefully take place at ESA’s Ministerial Council meeting (involving representatives from each of ESA’s member states) in November of 2025. To arrive at Apophis in February 2029, launch would have to take place in April 2028, the agency says.

This is a big deal because large asteroids don’t come this close to Earth very often. It is thus scientifically precious that, on April 13, 2029, Apophis will pass within 19,794 miles (31,860 kilometers) of Earth. For comparison, geosynchronous orbit is 22,236 miles (35,786 km) above Earth’s surface. Such close fly-bys by asteroids hundreds of meters across (Apophis is about 1,230 feet, or 375 meters, across) only occur on average once every 5,000 to 10,000 years. Miss this one, and we’ve got a long time to wait for the next.

When Apophis was discovered in 2004, it was for a short time the most dangerous asteroid known, being classified as having the potential to impact with Earth possibly in 2029, 2036, or 2068. Should an asteroid of its size strike Earth, it could gouge out a crater several kilometers across and devastate a country with shock waves, flash heating and earth tremors. If it crashed down in the ocean, it could send a towering tsunami to devastate coastlines in multiple countries.

Over time, as our knowledge of Apophis’ orbit became more refined, however, the risk of impact greatly went down. Radar observations of the asteroid in March of 2021 reduced the uncertainty in Apophis’ orbit from hundreds of kilometers to just a few kilometers, finally removing any lingering worries about an impact — at least for the next 100 years. (Beyond 100 years, asteroid orbits can become too unpredictable to plot with any accuracy, but there’s currently no suggestion that an impact will occur after 100 years.) So, Earth is expected to be perfectly safe in 2029 when Apophis comes through. Still, scientists want to see how Apophis responds by coming so close to Earth and entering our planet’s gravitational field.

“There is still so much we have yet to learn about asteroids but, until now, we have had to travel deep into the solar system to study them and perform experiments ourselves to interact with their surface,” said Patrick Michel, who is the Director of Research at CNRS at Observatoire de la Côte d’Azur in Nice, France, in a statement. “Nature is bringing one to us and conducting the experiment itself. All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface.”

The Goldstone radar’s imagery of asteroid 99942 Apophis as it made its closest approach to Earth, in March 2021. (Image credit: NASA/JPL–Caltech/NSF/AUI/GBO)

By arriving at Apophis before the asteroid’s close encounter with Earth, and sticking with it throughout the flyby and beyond, Ramses will be in prime position to conduct before-and-after surveys to see how Apophis reacts to Earth. By looking for disturbances Earth’s gravitational tidal forces trigger on the asteroid’s surface, Ramses will be able to learn about Apophis’ internal structure, density, porosity and composition, all of which are characteristics that we would need to first understand before considering how best to deflect a similar asteroid were one ever found to be on a collision course with our world.

Besides assisting in protecting Earth, learning about Apophis will give scientists further insights into how similar asteroids formed in the early solar system, and, in the process, how planets (including Earth) formed out of the same material.

One way we already know Earth will affect Apophis is by changing its orbit. Currently, Apophis is categorized as an Aten-type asteroid, which is what we call the class of near-Earth objects that have a shorter orbit around the sun than Earth does. Apophis currently gets as far as 0.92 astronomical units (137.6 million km, or 85.5 million miles) from the sun. However, our planet will give Apophis a gravitational nudge that will enlarge its orbit to 1.1 astronomical units (164.6 million km, or 102 million miles), such that its orbital period becomes longer than Earth’s.

It will then be classed as an Apollo-type asteroid.

Ramses won’t be alone in tracking Apophis. NASA has repurposed their OSIRIS-REx mission, which returned a sample from another near-Earth asteroid, 101955 Bennu, in 2023. However, the spacecraft, renamed OSIRIS-APEX (Apophis Explorer), won’t arrive at the asteroid until April 23, 2029, ten days after the close encounter with Earth. OSIRIS-APEX will initially perform a flyby of Apophis at a distance of about 2,500 miles (4,000 km) from the object, then return in June that year to settle into orbit around Apophis for an 18-month mission.

Science

McMaster Astronomy grad student takes a star turn in Killarney Provincial Park

Published

2 months ago

July 16, 2024

Harry Miller

Astronomy PhD candidate Veronika Dornan served as the astronomer in residence at Killarney Provincial Park. She’ll be back again in October when the nights are longer (and bug free). Dornan has delivered dozens of talks and shows at the W.J. McCallion Planetarium and in the community. (Photos by Veronika Dornan)

BY Jay Robb, Faculty of Science

July 16, 2024

Veronika Dornan followed up the April 8 total solar eclipse with another awe-inspiring celestial moment.

This time, the astronomy PhD candidate wasn’t cheering alongside thousands of people at McMaster — she was alone with a telescope in the heart of Killarney Provincial Park just before midnight.

Dornan had the park’s telescope pointed at one of the hundreds of globular star clusters that make up the Milky Way. She was seeing light from thousands of stars that had travelled more than 10,000 years to reach the Earth.

This time there was no cheering: All she could say was a quiet “wow”.

Dornan drove five hours north to spend a week at Killarney Park as the astronomer in residence. part of an outreach program run by the park in collaboration with the Allan I. Carswell Observatory at York University.

Dornan applied because the program combines her two favourite things — astronomy and the great outdoors. While she’s a lifelong camper, hiker and canoeist, it was her first trip to Killarney.

Bruce Waters, who’s taught astronomy to the public since 1981 and co-founded Stars over Killarney, warned Dornan that once she went to the park, she wouldn’t want to go anywhere else.

The park lived up to the hype. Everywhere she looked was like a painting, something “a certain Group of Seven had already thought many times over.”

The dome telescopes at Killarney Provincial Park.

She spent her days hiking the Granite Ridge, Crack and Chikanishing trails and kayaking on George Lake. At night, she went stargazing with campers — or at least tried to. The weather didn’t cooperate most evenings — instead of looking through the park’s two domed telescopes, Dornan improvised and gave talks in the amphitheatre beneath cloudy skies.

Dornan has delivered dozens of talks over the years in McMaster’s W.J. McCallion Planetarium and out in the community, but “it’s a bit more complicated when you’re talking about the stars while at the same time fighting for your life against swarms of bugs.”

When the campers called it a night and the clouds parted, Dornan spent hours observing the stars. “I seriously messed up my sleep schedule.”

She also gave astrophotography a try during her residency, capturing images of the Ring Nebula and the Great Hercules Cluster.

“People assume astronomers take their own photos. I needed quite a lot of guidance for how to take the images. It took a while to fiddle with the image properties, but I got my images.”

Dornan’s been invited back for another week-long residency in bug-free October, when longer nights offer more opportunities to explore and photograph the final frontier.

She’s aiming to defend her PhD thesis early next summer, then build a career that continues to combine research and outreach.

“Research leads to new discoveries which gives you exciting things to talk about. And if you’re not connecting with the public then what’s the point of doing research?”

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Science

Where in Vancouver to see the ‘best meteor shower of the year’

Published

2 months ago

July 16, 2024

Harry Miller

Eyes to the skies, Vancouver, because between now and September 1st, stargazers can witness the ‘best meteor shower of the year’ according to NASA.

Known for its “long wakes of light and colour,” the Perseid Meteor Shower will peak on August 12th, 2024 – so consider this list a great place to start if you’re in search of a prime stargazing spots!

Grab your lawn chairs and blankets, and seek as little light pollution as possible. Here are some ideal stargazing spots to check out in and around Vancouver this summer.

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Wreck Beach

If you’re willing to brave the stairs and the regulars, it doesn’t get much better than Wreck Beach for watching the skies – for both sunsets and stargazing. The west-facing views practically eliminate immediate distractions from the city lights.

Spanish Banks Park

Spanish Banks is the perfect mixture of convenience and quality. Its location offers unobstructed views of the skies above, and it’s far enough away from downtown to mitigate some of the light pollution.

Burnaby Mountain Park

If it’s good enough for a university observatory, it’s good enough for us. Pretty much anywhere on Burnaby Mountain will offer tremendous viewpoints, but the higher you get the better (safely).

Porteau Cove

A short drive from Vancouver gets you incredible views of the Howe Sound from directly on the water. And naturally, its distance from any nearby community makes it a prime spot for stargazing.

Cypress Mountain

In addition to having one of the best viewpoints in Vancouver period, Cypress Mountain (and the road up to it) is also a great place to watch the sky. For a double-whammy, we say that you come around sunset, then hang out while the sky gets dark. Sure, it might take a few hours, but the view is worth it.

So there you have it, stargazers! Get ready to witness a dazzling show this summer.

Isabelle Vauclair

Staff Writer, Vancouver

Isabelle is a west coast native with an appreciation for Vancouver’s natural landscape, patio scene, and community spaces. She loves to discover new hidden gems in her neighbourhood and share them with readers across the city.

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Science

Days are getting longer because of climate change, according to NASA

Published

2 months ago

July 15, 2024

Harry Miller

Rising sea levels are making each day slightly longer, and there’s no sign it’s going to stop, a new study funded in part by NASA and the Canadian government has found.

Published Monday, the paper from researchers in Canada, the United States and Switzerland studied the downstream effects of climate change on the very physics of the planet itself.

“Every single day has [a] slightly different length, because of so many factors, including … climate change,” said study co-author Surendra Adhikari in an interview with CTVNews.ca.

“This is … a testament of the gravity of ongoing climate change.”

The pale blue dot(-oid)

The relationship between carbon emissions and our choreography in the cosmic ballet comes down to something most Earthlings take for granted: The planet’s shape.

Contrary to popular belief, Planet Earth isn’t actually a perfect sphere. While the surface of land around the world is remarkably smooth on the planetary scale, what most forget to consider is water; in particular, how that water moves.

As the planet spins on its axis, the distribution of Earth’s oceans is impacted by that force, and like in a centrifuge, the liquid is pushed out from the centre, especially near the equator.

As a result, Earth, its oceans and all, bulges out at the middle, creating not a sphere, but a shape scientists refer to an oblate spheroid. That oblateness, or the size of the bulge at the equator, is central to Adhikari and co.’s findings.

In short, as rising global temperatures melt the polar ice caps, more of the Earth’s water supply is converted to liquid, allowing it to swell the oblate bulge along the equator, when it might previously have stayed locked away in the ice.

The swelling, in turn, changes the dynamics of how Earth spins in the first place, and invariably, the rotation decelerates.

“If you see how a figure skater controls their motion … if they have to slow down, they just extend their arms or legs, which is basically the same concept,” Adhikari explained. “It has everything to do with the conservation of angular momentum.”

A matter of milliseconds

Though days are measured at a standardized length of 86,400 seconds each, the actual time it takes for a point on the Earth’s surface to make a full rotation is getting ever-so-slightly longer, at a rate scientists say could get more severe as the perils of climate change deepen.

Relative to the age of the Earth, the 24-hour day is fairly new, a height reached after billions of years of growth. Five-hundred million years ago, a day-night cycle might have clocked just 22 hours in total; another billion years back, and scientists estimate something closer to 19 hours.

Historically, the rate of increase attributable to climate change has been slow, hovering between 0.3 and one added daily millisecond each 100 years between 1900 and 2000. But as the industrial revolution’s aftereffects have intensified, the rate has grown, clocking in at roughly 1.33 milliseconds per day, per century, since the turn of the millenium.

Adhikari and his colleagues’ research found that in a high-emissions scenario, by 2100, it could surpass 2.5 milliseconds, marking the first time that humanity’s influence on the Earth’s spin would be greater than that of the Moon and the tides.

“Over the course of Earth’s geological evolution, tidal friction by the moon has been the dominant cause of the … increase in [length of day],” the study concludes.

“If, however, greenhouse gas emissions continue to rise, the increase in atmospheric and oceanic warming and associated ice melting will lead to a much higher rate … becoming the most important contribution to the long-term [length-of-day] variations.”

Time to get a new watch?

In practical terms, a few extra milliseconds per day over the course of a human lifetime isn’t the most pressing impact of climate change, though Adhikari notes that computer systems, which rely on the 86,400-second day, may require an adjustment as the intricacies of time start to pass out of sync.

It’s a problem that physicists and computer scientists alike have monitored since the 1970s, long understood to require occasionally shoehorning an extra “leap second” into counts by atomic clocks to avoid widespread logistical headaches.

According to a recent study from the University of California San Diego, the impacts of climate change on the Earth’s rotation might further complicate when and how those leap seconds need to be inserted; an additional piece of a vexing international puzzle.

“This will pose an unprecedented problem for computer network timing,” the study reads. “Global warming is already affecting global timekeeping.”

Whether the Earth’s spin brings on its own mini-Y2K any time soon, Adhikari says the NASA study’s findings stand as a symbol for humanity’s influence on our planet, that in just a few hundred years of industrialization, the side effects may some day surpass those of the massive celestial body hanging in our night sky.

“It’s really profound,” he said. “In a way, we have messed up our climate system so much so that we are witnessing its impact on the very way our Earth spins … a tiny human being, who is doing some stupid things, and making this happen.”

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