A Transit of Mercury Happens Nov. 11

The sky will put on a show Nov. 11 when Mercury journeys across the Sun. The event, known as a transit, occurs when Mercury passes directly between Earth and the Sun. From our perspective on Earth, Mercury will look like a tiny black dot gliding across the Sun’s face. This only happens about 13 times a century, so it’s a rare event that skywatchers won’t want to miss! Mercury’s last transit was in 2016.  The next won’t happen again until 2032!

“Viewing transits and eclipses provide opportunities to engage the public, to encourage one and all to experience the wonders of the universe and to appreciate how precisely science and mathematics can predict celestial events,” said Mitzi Adams, a solar scientist in the Heliophysics and Planetary Science Branch at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Of course, safely viewing the Sun is one of my favorite things to do.”

This year’s transit will be widely visible from most of Earth, including the Americas, the Atlantic and Pacific Oceans, New Zealand, Europe, Africa, and western Asia. It starts at about 6:35 a.m. CST, but viewers in some areas, such as the West Coast, will have to wait until the Sun rises at their location to see the transit already in progress. Thankfully, this transit will last almost six hours, so there will be plenty of time to catch the show. At about 9:20 a.m. CST, Mercury’s center will be as close as it is going to get to the Sun’s.

Mercury’s tiny disk, jet black and perfectly round, covers a tiny fraction of the Sun’s blinding surface — only 1/283 of the Sun’s apparent diameter. So you’ll need the magnification of a telescope (minimum of 50x) with a solar filter to view the transit. Never look at the Sun directly or through a telescope without proper protection. It can lead to serious and permanent vision damage. Always use a safe Sun filter to protect your eyes!

Scientists have been using transits for hundreds of years to study the way planets and stars move in space. Edmund Halley used a transit of Venus in 1761 and 1769 to determine the absolute distance to the Sun. Another use of transits is the dimming of Sun or star light as a planet crosses in front of it. This technique is one way planets circling other stars can be found. Scientists can measure brightness dips from these other stars (or from the Sun) to calculate sizes of planets, how far away the planets are from their stars, and even get hints of what they’re made of.

Out With the Harvest, In With the Hunt

The International Observe the Moon Night is happening Oct. 5!

In the wake of the beautiful Harvest Moon seen Sept. 14, Earth’s satellite now enters its waning phase, shrinking slice by slice into a visible semicircle as the rotating Earth spins around the Sun and its shadow is cast past us onto the Moon.

This period of waxing or waning is commonly known as a “gibbous” period, a term meaning “convex” or “rounded.” The term originated in the 15th century, though the Oxford English Dictionary suggests it was first applied to describe the Moon in 1690.

Gradually, over the coming month, the Moon will cycle toward its next full period – the Hunter’s Moon, also known as the Blood Moon or Sanguine Moon, due in mid-October. Various Native American tribes gave the Moon this name to reflect the falling leaves of autumn and the fattening of deer and other animals to prepare for the winter to come.

Speaking of coming events, the International Observe the Moon Night is happening Oct. 5! Learn more about NASA’s plans and how you can join in the fun here.

Look for the Harvest Moon this Weekend

Take a moment this weekend to gaze at the beautiful Harvest Moon! The Moon will appear full Thursday night through Sunday morning. Early Saturday morning, Sept. 14, will mark the actual full Moon.

The Harvest Moon gets its name from agriculture. In the days before electric lights, farmers across the Northern Hemisphere depended on bright moonlight to extend the workday beyond sunset. It was the only way they could gather their ripening crops in time for market. The full Moon closest to the autumnal equinox became “the Harvest Moon,” and it was always a welcome sight.

The term became further entrenched in popular culture thanks to a 1903 pop tune called “Shine on Harvest Moon.”

A Harvest Moon inflated by the moon illusion — a common phenomenon with full moons seen close to the horizon, where familiar Earth objects such as trees or buildings lend the Moon a false sense of size — is simply beautiful to view, but even more so to the farmers gathering their crops in on those cool autumn evenings.

Go Outside and See Mars!

35.8 million miles is definitely not what most of us would consider “close.” But in planetary terms, close is definitely relative! On July 31, Mars will be 35.8 million miles from Earth, which is the closest it has been to Earth in 15 years. What does this mean for sky watchers? It means the Red Planet will appear super bright, and with its orange-red color, will be hard to miss in the nighttime sky. From July 27-30, the point in Mars’ orbit will come closest to Earth, and will be closest to Earth before sunrise Eastern Time on July 31.

What defines a “close approach?” The minimum distance from the Earth to Mars is about 33.9 million miles and does not happen very often. Because Earth and Mars have elliptical orbits and are slightly tilted to each other, all close approaches are not equal. When Mars slowly approaches what astronomers call opposition, it and the Sun are on opposite sides of the Earth. Earth and Mars align in opposition about every two years (fun fact: this is why most NASA missions to the Red Planet are at least two years apart – to take advantage of the closer distance). Opposition to Mars is at its closest to the Sun every 15 to 17 years, when excellent views of the Red Planet from Earth can occur. This is what is happening on the early morning hours of July 31.

Mars is the fourth planet from the sun.
Mars is the fourth planet from the sun.
Image credit: NASA

Is 35.8 million miles the closest Mars has ever been to Earth? Nope. In 2003, Mars was 34.6 million miles from Earth and the closest it had been in nearly 60,000 years. This type of proximity won’t occur again until 2287. But, there will be another close approach in October 2020 when the distance between the Red Planet and Earth will be 38.6 million miles.

Now that we’ve gotten all of that out of the way, what does this mean for you, the novice astronomer or general sky-watcher? It means that if you have clear skies where you live, go outside on the overnight hours of July 30 or early morning hours of July 31 and look up. The planet will be brighter than usual and will have an orange or red haze. You can also look through a telescope. If weather is bad where you are, NASA will be streaming live from the Griffith Observatory.

Good luck and happy viewing!

Fireball spotted northwest of Chicago, February 6, 1:25 AM CST

There was a very bright green fireball seen by hundreds of eyewitnesses surrounding Lake Michigan early this morning at 1:25:13 AM Central Time (February 6, 2017). The reports from these individuals and the video information from dash cameras and other cameras in the region indicate that the meteor originated 62 miles above West Bend, Wisconsin and moved northeast at about 38,000 miles per hour. It disrupted about 21 miles above Lake Michigan, approximately 9 miles east of the town of Newton. The explosive force of this disruption was recorded on an infrasound station in Manitoba, some 600 miles away – these data put the lower limit energy of the event at about 10 tons of TNT, which means we are dealing with a meteoroid – orbit indicates an asteroidal fragment – weighing at least 600 pounds and 2 feet in diameter. Doppler weather radar picked up fragments (meteorites) falling into Lake Michigan near the end point of the trajectory.

Ground track and Doppler radar signature (done by Marc Fries at NASA Johnson Space Center); an animation of the orbit and approach of the meteoroid is being prepared and should be available soon. We will continue to look at data as it comes in and revise the calculations if necessary.

Links to videos of this event:

Lisle, IL Police Department
https://www.youtube.com/watch?v=cF0POBcZQRk

From Highway in Wisconsin:
https://twitter.com/KrazyPhukinFoo/status/828543708299657216
https://www.youtube.com/watch?v=-AozuKJZK_4

Chillicothe IL Police Department:
https://twitter.com/chillipd?ref_src=twsrc%5Etfw

Morton Grove Police Squad
https://twitter.com/NWSChicago/status/828532116300394496

Roof of Atmospheric, Oceanic & Space Sciences Building – University of Wisconsin https://www.youtube.com/watch?v=LHubXCtdEbo

EarthCams:

Looking over Lake Michigan, from Michigan Coast: (looking too north to see the meteor itself) http://www.earthcam.com/usa/michigan/grandhaven/lakemichigan/?cam=lakemichigan
Bright flash at 2:25:13

Images from the Peak of the Orionid Meteor Shower

A bright Orionid is captured on the peak night of the shower by a NASA all sky meteor camera in western North Carolina.

Orionid_1

An Orionid cuts across Orion’s shoulders in this video recorded by a NASA wide field meteor camera at Marshall Space Flight Center. The 3 stars of Orion’s belt are clearly visible in the lower left corner of the image.

Orion_2

An Orionid heads south towards Orion’s belt in this video recorded by a NASA wide field meteor camera at Marshall Space Flight Center.

orionid_3

Bright Sky Event Over Southeastern United States – June 29

Meteor across SEComposite image showing bright event located near Rosman, North Carolina.

There was a bright event seen across several Southeast states last night at 12:29:30 AM CDT (1:29:30 EDT). Based on the data we currently have, this object was not a meteor or fireball. Tracked by 5 NASA cameras in the SE, it is moving at roughly 14,500 miles per hour, which is too slow to be a meteor. As you can see in the video, it has also broken into multiple pieces, which, combined with the slow speed, indicates a possible reentry of space debris. There are over 120 eyewitness accounts on the American Meteor Society website (www.amsmeteors.org)

https://www.youtube.com/watch?v=https://youtu.be/9LgpqyDMu0U[/embedyt]

https://www.youtube.com/watch?v=https://youtu.be/Vmq9k9hOXDs[/embedyt]

Lyrid Meteor Shower Peaks Tomorrow, April 22

Dust off the lawn chairs and get ready for the peak of the Lyrid meteor shower which will occur on the night of April 22.

“The Lyrids are really unpredictable,” Cooke said. “For the 2015 shower, I’m expecting 15 to 20 Lyrid meteors an hour. Peak rates should occur after 10:30 PM on April 22 your local time, for observers in the northern hemisphere. For observers in the southern hemisphere, Lyrid rates are not significant until after midnight your local time.”

Viewing tips for the Lyrids

No special equipment is needed to watch a meteor shower. Simply find a dark, open sky away from artificial lights. Lie down comfortably on a blanket or lawn chair, and look straight up.

A camera, provided by scientists at NASA’s Marshall Space Flight Center, will offer a live feed of the Lyrids beginning at 10:00 PM CDT.The camera is light-activated, and will switch on at nightfall. During daytime hours, the webcast will show recorded views of past meteor showers.

Watch the live feed here.

About the Lyrids

Lyrids are pieces of debris from the periodic Comet C/1861 G1 Thatcher and have been observed for more than 2,600 years. In mid-April of each year, Earth runs into the stream of debris from the comet, which causes the Lyrid meteor shower. You can tell if a meteor belongs to a particular shower by tracing back its path to see if it originates near a specific point in the sky, called the radiant. The constellation in which the radiant is located gives the shower its name, and in this case, Lyrids appear to come from a point in the constellation Lyra.

Lyridsequence_20140422_092714_04

Ask an Astronomer About the Shortest Lunar Eclipse of the Century on April 4

On Saturday morning, April 4, 2015 not long before sunrise, the bright full moon over North America should turn a lovely shade of celestial red during a total lunar eclipse. Join NASA astronomer Mitzi Adams as she takes questions via Twitter @NASA_Marshall. For Twitter questions, use the hashtag #eclipse2015. The question and answer via Twitter will begin at 6 a.m. EDT and continue through the end of the eclipse (approximately 8:00 a.m. EDT on April 4).

The lunar eclipse will be visible from all parts of the United States.  Eastern North America and western South America can see beginning stages of the partial umbral eclipse low in the west before sunrise April 4, whereas middle Asia (India, western China, mid-Asian Russia) can view the ending stages of the partial umbral eclipse low in the east after sunset April 4. Greenland, Iceland, Europe, Africa and the Middle East won’t see this eclipse at all. A world map of eclipse visibility is available here. The total eclipse will last only five minutes. You can find more information  here.

This image shows the Dec. 20, 2012 total lunar eclipse, as seen from Sagamihara, Japan.
This image shows the Dec. 20, 2012 total lunar eclipse, as seen from Sagamihara, Japan.