For more than seven hours on Monday, May 9, Mercury will be visible as a tiny black dot crossing the face of the sun. This rare event – which happens only slightly more than once a decade – is called a transit.
Although Mercury whips around the sun every 88 days – over four times faster than Earth – the three bodies rarely align. Because Mercury orbits in a plane 7 degrees tilted from Earth’s orbit, it usually darts above or below our line of sight to the sun. As a result, a Mercury transit happens only about 13 times a century. The last one was in 2006, and the next one isn’t until 2019.
When: On May 9, shortly after 7:00 a.m. EDT, Mercury will appear as a tiny black dot against a blazing backdrop, traversing the sun’s disk over seven and a half hours. Mercury will cross the edge of the sun (ingress) after 7:00 a.m. EDT. The mid-transit point will occur a little after 10:45 a.m. EDT, with egress around 2:30 p.m. EDT.
Where: Skywatchers in Western Europe, South America and eastern North America will be able to see the entirety of the transit. The entire 7.5-hour path across the sun will be visible across the Eastern U.S. – with magnification and proper solar filters – while those in the West can observe the transit in progress at sunrise.
Unlike the 2012 Venus transit of the sun, Mercury is too small to be visible without magnification from a telescope or high-powered binoculars. Both must have safe solar filters made of specially-coated glass or Mylar; you can never look directly at the sun. We’re offering several avenues for the public to view the event without specialized and costly equipment, including images on NASA.gov, a one-hour NASA Television special, and social media coverage.
Transits like this allowed scientists in the 17th century to make the first estimates of Earth’s distance from the sun. Transit observations over the past few centuries have also helped scientists study everything from the atmosphere of Venus to the slight shifts in Mercury’s orbit that could only be explained by the theory of general relativity. Because we know Mercury’s size and location precisely, this transit will help scientists calibrate telescopes on solar observatories SDO, SOHO, and Hinode.
Transits can also teach us more about planets – both in and out of our solar system. The Venus transit in 2012 provided observations of the planet's atmosphere. Transits are also the main way we find planets outside the solar system, called exoplanets.
The transit method looks for a drop in the brightness of a star when a planet passes in front of it. This method will not find every planet – only those that happen to cross our line of sight from Earth to the star. But with enough sensitivity, the transit method through continuous monitoring is a great way to detect small, Earth-size planets, and has the advantage of giving us both the planet’s size (from the fraction of starlight blocked), as well as its orbit (from the period between transits). Our Kepler/K2 mission uses this method to find exoplanets, as will the Transiting Exoplanet Survey Satellites, or TESS, following its launch in 2017/2018.
We will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 a.m. -- an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA.
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Is earth doing fine, I'm afraid of all the bad stuff that's happening. I just wanna know if it's doing okay (◍•﹏•)
In recent years of tracking weather activity and the like, have there been more 'anomolies' that have stuck out more than others? (I.E hurricanes, typhoons or cyclones that start out as small storms then become hurricane 4-5 storms in a matter of days-weeks) I think what you guys are doing is awesome and keep up the good work ~TKL
The universe is filled with billions upon billions of stars. Look up at the night sky, and you can see a small fraction of them, each appearing as a tiny pinprick of light against the inky blackness of space. But did you know there’s more to space than our eyes can see? To observe the hidden cosmos, we use telescopes that can see in the infrared. How do stars and planets form? How do black holes feast? How does matter escape galaxies? These are all questions we can begin to answer by exploring space in this wavelength of light. The infrared views captured by SOFIA, the world’s largest flying observatory, have helped us uncover mysterious objects and phenomena in our galaxy and beyond! The findings are changing our understanding of the way in which the universe works. Here are five cool scientific discoveries made by the mission.
SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Learn more about the mission: www.nasa.gov/sofia
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On April 17, NASA's New Horizons crossed a rare deep-space milestone – 50 astronomical units from the Sun, or 50 times farther from the Sun than Earth is. New Horizons is just the fifth spacecraft to reach this great distance, following the legendary Voyagers 1 and 2 and Pioneers 10 and 11. It’s almost 5 billion miles (7.5 billion kilometers) away; a remote region where a signal radioed from NASA's largest antennas on Earth, even traveling at the speed of light, needs seven hours to reach the far-flung spacecraft.
To celebrate reaching 50 AU, the New Horizons team compiled a list of 50 facts about the mission. Here are just a few of them; you'll find the full collection at: http://pluto.jhuapl.edu/News-Center/Fifty-Facts.php.
New Horizons is the first – and so far, only – spacecraft to visit Pluto. New Horizons sped through the Pluto system on July 14, 2015, providing a history-making close-up view of the dwarf planet and its family of five moons.
New Horizons is carrying some of the ashes of Pluto’s discoverer, Clyde Tombaugh. In 1930, the amateur astronomer spotted Pluto in a series of telescope images at Lowell Observatory in Arizona, making him the first American to discover a planet.
The “Pluto Not Yet Explored” U.S. stamp that New Horizons carries holds the Guinness World Record for the farthest traveled postage stamp. The stamp was part of a series created in 1991, when Pluto was the last unexplored planet in the solar system.
Dispatched at 36,400 miles per hour (58, 500 kilometers per hour) on January 19, 2006, New Horizons is still the fastest human-made object ever launched from Earth.
As the spacecraft flew by Jupiter’s moon Io, in February 2007, New Horizons captured the first detailed movie of a volcano erupting anywhere in the solar system except Earth.
New Horizons’ radioisotope thermoelectric generator (RTG) – its nuclear battery – will provide enough power to keep the spacecraft operating until the late-2030s.
Measurements of the universe’s darkness using New Horizons data found that the universe is twice as bright as predicted – a major extragalactic astronomy discovery!
New Horizons’ Venetia Burney Student Dust Counter is the first student-built instrument on any NASA planetary mission – and is providing unprecedented insight into the dust environment in the outer solar system.
New Horizons is so far away, that even the positons of the stars look different than what we see from Earth. This view of an "alien sky" allowed scientists to make stereo images of the nearest stars against the background of the galaxy.
Arrokoth – the official name the mission team proposed for the Kuiper Belt object New Horizons explored in January 2019 – is a Native American term that means “sky” in the Powhatan/Algonquin language.
Stay tuned in to the latest New Horizons updates on the mission website and follow NASA Solar System on Twitter and Facebook.
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About 45 million light-years away, in another corner of the cosmos, lies spiral galaxy NGC 1097. Though this Hubble Space Telescope image zooms in toward the core, the galaxy’s vast spiral arms span over 100,000 light-years as they silently sweep through space. At the heart of this galaxy lurks a black hole that is about 100 million times as massive as the Sun.
The supermassive black hole is voraciously eating up surrounding matter, which forms a doughnut-shaped ring around it. Matter that's pulled into the black hole releases powerful radiation, making the star-filled center of the galaxy even brighter. Hubble’s observations have led to the discovery that while the material that is drawn toward NGC 1097’s black hole may be doomed to die, new stars are bursting into life in the ring around it.
This sparkling spiral galaxy is especially interesting to both professional scientists and amateur astronomers. It is a popular target for supernova hunters ever since the galaxy experienced three supernovas in relatively rapid succession — just over a decade, between 1992 and 2003. Scientists are intrigued by the galaxy’s satellites — smaller “dwarf” galaxies that orbit NGC 1097 like moons. Studying this set of galaxies could reveal new information about how galaxies interact with each other and co-evolve.
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The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun’s intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy.
If the sun were as tall as a typical front door, the Earth would be the size of a U.S. nickel
The temperature at the sun’s core is about 27 million degrees Fahrenheit
Our sun is more massive than the average star in its neighborhood. Nearly 90% of stars are less massive, making them cooler and dimmer
The sun contains 99.9% of all matter in our solar system
During a single second, the sun converts 4 million tons of matter to pure energy
It would take about 1 million Earths to fill the sun if it were a hollow ball
The sun rotates on its axis approximately once every 27 days
The sun is 93 million miles away from Earth and is almost 5 billion years old
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Let the planet-hunting begin!
Our Transiting Exoplanet Survey Satellite (TESS), which will scan the skies to look for planets beyond our solar system—known as exoplanets—is now in Florida to begin preparations for launch in April. Below, 10 Things to know about the many, many unknown planets out there awaiting our discovery.
We call planets in our solar system, well, planets, but the many planets we’re starting to discover outside of our solar system are called exoplanets. Basically, they’re planets that orbit another star.
Remember the major 2016 announcement that we had discovered seven planets 40 light-years away, orbiting a star called TRAPPIST-1? Those are all exoplanets. (Here’s a refresher.)
Just last month, our Kepler telescope discovered 95 new exoplanets beyond our solar system (on top of the thousands of exoplanets Kepler has discovered so far). The total known planet count beyond our solar system is now more than 3,700. The planets range in size from mostly rocky super-Earths and fluffy mini-Neptunes, to Jupiter-like giants. They include a new planet orbiting a very bright star—the brightest star ever discovered by Kepler to have a transiting planet.
How many more exoplanets are out there waiting to be discovered? TESS will monitor more than 200,000 of the nearest and brightest stars in search of transit events—periodic dips in a star’s brightness caused by planets passing in front—and is expected to find thousands of exoplanets.
Our upcoming James Webb Space Telescope, will provide important follow-up observations of some of the most promising TESS-discovered exoplanets. It will also allow scientists to study their atmospheres and, in some special cases, search for signs that these planets could support life.
TESS is scheduled to launch on a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station nearby our Kennedy Space Center in Florida, no earlier than April 16, pending range approval.
In 1995, 51 Pegasi b (also called "Dimidium") was the first exoplanet discovered orbiting a star like our Sun. This find confirmed that planets like the ones in our solar system could exist elsewhere in the universe.
A recent statistical estimate places, on average, at least one planet around every star in the galaxy. That means there could be a trillion planets in our galaxy alone, many of them in the range of Earth’s size.
Of course, our ultimate science goal is to find unmistakable signs of current life. How soon can that happen? It depends on two unknowns: the prevalence of life in the galaxy and a bit of luck. Read more about the search for life.
No need to be an astronaut. Take a trip outside our solar system with help from our Exoplanet Travel Bureau.
Read the full version of this week’s ‘10 Things to Know’ article HERE.
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