NASA launched the Artemis I mission from Florida at 1:47 a.m. ET on Wednesday morning, with the agency’s most powerful rocket ever kicking off a nearly month-long journey with a ground-shaking liftoff.
While no astronauts are onboard, the Space Launch System (SLS) rocket carried the Orion capsule to space in a demonstration for NASA’s lunar program. Artemis I will not land on the moon, but the spacecraft will orbit nearby before returning to Earth in 26 days.
In the final hours of the countdown, a hydrogen leak in a valve threatened to delay the launch. With SLS nearly fully fueled, a small group known as the “red team” was sent out to the launchpad and into the “blast danger area” to try to fix the problem. The team was able to tighten hardware on the leaky valve and returned to safety, with NASA’s launch then able to proceed.
So far the mission is going as planned, with Orion reaching orbit around the Earth at about 2 a.m. ET and firing its engines about two hours after launch to begin the multi-day trip to the moon.
The next major milestone is set for Nov. 21, when Orion will make its closest approach to the moon of 60 miles above the surface. To return, Orion will use the moon’s gravity to assist it in setting a trajectory back into Earth’s orbit. Artemis I will travel about 1.3 million miles over the course of the mission.
The mission represents a crucial inflection point in NASA’s moon plans, with the program delayed for years and running billions of dollars over budget. The Artemis program represents a series of missions with escalating goals. The third – tentatively scheduled for 2025 – is expected to return astronauts to the lunar surface for the first time since the Apollo era.
By Sarah Lewin Space.com – According to NASA meteor expert Bill Cooke, the Perseids are perhaps the most popular meteor shower of the year; and in 2018, they’ll be the best shower of the year. During the Perseids’ peak this weekend, spectators should see about 60-70 meteors per hour, but in outburst years (such as in 2016) the rate can be between 150-200 meteors an hour. The meteor shower’s peak will be visible both the nights of Aug. 11-12 and Aug. 12-13, Cooke said, but he’s inclined this year to lean toward the night of Aug. 12-13 for the better show. (Both, however, should be spectacular.)
“This year the moon will be near new moon, it will be a crescent, which means it will set before the Perseid show gets underway after midnight,” Cooke told Space.com. “The moon is very favorable for the Perseids this year, and that’ll make the Perseids probably the best shower of 2018 for people who want to go out and view it.” The Perseids are rich in fireballs, so the show should be even better.
To best see the Perseids, go to the darkest possible location and lean back to observe as much sky as possible directly above you. The rates of Perseids visible will increase from about 10 p.m. in your local time zone all the way through dawn, so the later you can look the better. Earlier in the night there will be fewer meteors, but the ones that appear will have longer tails as they graze along more of the atmosphere. Those in southern latitudes can look toward the northeast to see more meteors.
The 2018 Perseid meteor shower peaks overnight on Aug. 12-13, 2018. This sky map shows where to look at 11 p.m. local time this weekend. Credit: Sky & Telescope Magazine
Skywatchers looking out for the Perseids should also be able to see Mars (visible until about 4 a.m. in your local time zone) and Saturn (visible until about 2 a.m. local time); Venus and Jupiter both set before the Perseids are best viewed (9:30 p.m. and 11 p.m., respectively).
Earth will pass through the path of Comet Swift-Tuttle from July 17 to Aug. 24, with the shower’s peak — when Earth passes through the densest, dustiest area — occurring on Aug. 12. That means you’ll see the most meteors in the shortest amount of time near that peak, but you can still catch some action from the famed meteor shower before or after that point.
You can see the Perseid meteor shower best in the Northern Hemisphere and down to the mid-southern latitudes, and all you need to catch the show is darkness, somewhere comfortable to sit and a bit of patience.
What causes the Perseids?
Comet Swift-Tuttle is the largest object known to repeatedly pass by Earth; its nucleus is about 16 miles (26 kilometers) wide. It last passed nearby Earth during its orbit around the sun in 1992, and the next time will be in 2126. But it won’t be forgotten in the meantime, because Earth passes through the dust and debris it leaves behind every year, creating the annual Perseid meteor shower.
The annual Perseid meteor shower occurs when the Earth passes through a stream of dust from the Comet Swift-Tuttle, as shown in this orbit diagram. Credit: Sky & Telescope Magazine
When you sit back to watch a meteor shower, you’re actually seeing the pieces of comet debris heat up as they enter the atmosphere and burn up in a bright burst of light, streaking a vivid path across the sky as they travel at 37 miles (59 km) per second. When they’re in space, the pieces of debris are called “meteoroids,” but when they reach Earth’s atmosphere, they’re designated as “meteors.” If a piece makes it all the way down to Earth without burning up, it graduates to “meteorite.” Most of the meteors in the Perseids are much too small for that; they’re about the size of a grain of sand.
What do you need to see them?
The key to seeing a meteor shower is “to take in as much sky as possible,” Cooke said. Go to a dark area, in the suburbs or countryside, and prepare to sit outside for a few hours. It takes about 30 minutes for your eyes to adjust to the dark, and the longer you wait outside, the more you’ll see. A rate of 60-70 meteors per hour, for instance, means around one meteor per minute, including faint streaks along with bright, fireball-generating ones.
Some skywatchers plan to camp out to see the Perseid meteor shower, but at the very least, viewers should bring something comfortable to sit on, some snacks and some bug spray. Then, just relax and look upward for the celestial show.
