Mercury is the smallest planet in our solar system and is only slightly larger than Earth’s moon. To give you some perspective, if the sun were as tall as a typical front door, Earth would be the size of a nickel and Mercury would be about as big as a green pea.
Mercury is the closest planet to the sun. Daytime temperatures can reach 430 degrees Celsius (800 degrees Fahrenheit) and drop to –180 degrees Celsius (-290 degrees Fahrenheit) at night.
Here are a few fun facts about Mercury:
Mercury takes only 88 Earth days to orbit the sun
If we could stand on Mercury’s surface when it is at its closest point to the sun, the sun would appear more than three times larger than it does here on Earth
Mercury is home to one of the largest impact basins in the solar system: the Caloris Basin. The diameter of this impact basin is the length of 16,404 football fields (minus the end zones) placed end to end!
Mercury is one of only two planets in our solar system that do not have moons (Venus is the other one)
Mercury completes three rotations for every two orbits around the sun. That means that if you wanted to stay up from sunrise to sunrise on Mercury, you’d be up for 176 Earth days…you’d need a LOT of coffee!
Two missions have visited Mercury:
Mariner 10 was the first mission to Mercury, and 30 years later, our MESSENGER mission was the second to visit the planet. Mariner 10 was also the first spacecraft to reach one planet by using the gravity of another planet (in this case, Venus) to alter its speed and trajectory.
MESSENGER was the first spacecraft to orbit Mercury, The spacecraft had its own shades to protect it from the light of the sun. This is important since sunlight on Mercury can be as much as 11 times brighter than it is here on Earth. The spacecraft was originally planned to orbit Mercury for one year, but exceeded expectations and worked for over four years capturing extensive data. On April 30, 2015, the spacecraft succumbed to the pull of solar gravity and impacted Mercury’s surface.
Water Ice?
The MESSENGER spacecraft observed compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.
This radar image of Mercury’s north polar region. The areas shown in red were captured by MESSENGER, compared to the yellow deposits imaged by Earth-based radar. These areas are believed to consist of water ice.
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.
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.
Watch: 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. 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.
To learn more about our solar system and the planets, visit: http://solarsystem.nasa.gov/
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4th Hottest
2018 was the fourth hottest year since modern recordkeeping began. NASA and the National Oceanic and Atmospheric Administration work together to track temperatures around the world and study how they change from year to year. For decades, the overall global temperature has been increasing.
Over the long term, world temperatures are warming, but each individual year is affected by things like El Niño ocean patterns and specific weather events.
1.5 degrees
Globally, Earth’s temperature was more than 1.5 degrees Fahrenheit warmer than the average from 1951 to 1980.
139 years
Since 1880, we can put together a consistent record of temperatures around the planet and see that it was much colder in the late-19th century. Before 1880, uncertainties in tracking global temperatures were too large. Temperatures have increased even faster since the 1970s, the result of increasing greenhouse gases in the atmosphere.
Five Hottest
The last five years have been the hottest in the modern record.
6,300 Individual Observations
Scientists from NASA use data from 6,300 weather stations and Antarctic research stations, together with ship- and buoy-based observations of sea surface temperatures to track global temperatures.
605,830 swimming pools
As the planet warms, polar ice is melting at an accelerated rate. The Greenland and Antarctic ice sheets lost about 605,830 Olympic swimming pools (400 billion gallons) of water between 1993 and 2016.
8 inches
Melting ice raises sea levels around the world. While ice melts into the ocean, heat also causes the water to expand. Since 1880, sea levels around the world have risen approximately 8 inches.
71,189 acres burned
One symptom of the warmer climate is that fire seasons burn hotter and longer. In 2018, wildfires burned more than 71,189 acres in the U.S. alone.
46% increase in CO2 levels
CO2 levels have increased 46 percent since the late 19th Century, which is a dominant factor causing global warming.
The solar system is vast, and exploring it requires not one expedition, but many. From the sun to the Earth to the depths of space beyond Pluto, an entire fleet of spacecraft is pushing back the frontiers of knowledge. Scientists and engineers around the world work together on dozens of missions, and the results of their work unfold on a daily basis. During any given week, astronauts and robotic spacecraft return thousands of pictures and other data from Earth orbit and from half a dozen other worlds.
The result? It’s nothing short of a visual and intellectual feast. For example, all of the following images were obtained over the course of one week during January this year.
The same missions that took these pictures are still at work – they may be photographing Saturn or transmitting a report from Mars as you read this.
1. The Sun
From its clear vantage point in Earth orbit, our Solar Dynamics Observatory (SDO) observes our nearby star almost continuously. This image shows activity on the sun’s surface on Jan. 18. You can also get similar pictures from SDO daily!
2. The Earth from Afar
The DSCOVR satellite orbits the Earth at a distance of nearly a million miles (1.5 million kilometers). It’s Earth Polychromatic Imaging Camera (EPIC) keeps a steady watch on the home planet. This is how the world turned on Jan. 20. Get the latest daily images from EPIC HERE.
3. Mars from Above
The team that manages the Mars Reconnaissance Orbiter (MRO) recently celebrated a decade of observing the Red Planet. MRO took this detailed look at dunes and rocky buttes in Danielson Crater on Jan. 24. It was 3:06 p.m., local Mars time. On the right stide of the image, dust devils have left tracks in the sand.
4. Comet 67/P
The European Space Agency’s Rosetta probe caught this look at the surface of Comet 67/P from a distance of just 46 miles (75 kilometers) on Jan. 23.
5. Saturn
On the same day (Jan. 23), our Cassini spacecraft continued its odyssey of nearly two decades in space, bringing us this look at the sixth planet. See the latest images from Cassini HERE.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
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Award-winning NASA mathematician and computer programmer Melba Mouton is being honored with the naming of a mountain at the Moon’s South Pole. Mouton joined NASA in 1959, just a year after the space agency was established. She was the leader of a team that coded computer programs to calculate spacecraft trajectories and locations. Her contributions were instrumental to landing the first humans on the Moon.
She also led the group of "human computers," who tracked the Echo satellites. Roy and her team's computations helped produce the orbital element timetables by which millions could view the satellite from Earth as it passed overhead.
The towering lunar landmark now known as “Mons Mouton” stands at a height greater than 19,000 feet. The mountain was created over billions of years by lunar impacts. Huge craters lie around its base—some with cliff-like edges that descend into areas of permanent darkness. Mons Mouton is the future landing site of VIPER, our first robotic Moon rover. The rover will explore the Moon’s surface to help gain a better understanding of the origin of lunar water. Here are things to know:
The VIPER mission is managed by our Ames Research Center in California’s Silicon Valley. The approximately 1,000-pound rover will be delivered to the Moon by a commercial vendor as part of our Commercial Lunar Payload Services initiative, delivering science and technology payloads to and near the Moon.
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On August 6, 1967, astrophysicist Jocelyn Bell Burnell noticed a blip in her radio telescope data. And then another. Eventually, Bell Burnell figured out that these blips, or pulses, were not from people or machines.
The blips were constant. There was something in space that was pulsing in a regular pattern, and Bell Burnell figured out that it was a pulsar: a rapidly spinning neutron star emitting beams of light. Neutron stars are superdense objects created when a massive star dies. Not only are they dense, but neutron stars can also spin really fast! Every star we observe spins, and due to a property called angular momentum, as a collapsing star gets smaller and denser, it spins faster. It’s like how ice skaters spin faster as they bring their arms closer to their bodies and make the space that they take up smaller.
The pulses of light coming from these whirling stars are like the beacons spinning at the tops of lighthouses that help sailors safely approach the shore. As the pulsar spins, beams of radio waves (and other types of light) are swept out into the universe with each turn. The light appears and disappears from our view each time the star rotates.
After decades of studying pulsars, astronomers wondered—could they serve as cosmic beacons to help future space explorers navigate the universe? To see if it could work, scientists needed to do some testing!
First, it was important to gather more data. NASA’s NICER, or Neutron star Interior Composition Explorer, is a telescope that was installed aboard the International Space Station in 2017. Its goal is to find out things about neutron stars like their sizes and densities, using an array of 56 special X-ray concentrators and sensitive detectors to capture and measure pulsars’ light.
But how can we use these X-ray pulses as navigational tools? Enter SEXTANT, or Station Explorer for X-ray Timing and Navigation Technology. If NICER was your phone, SEXTANT would be like an app on it.
During the first few years of NICER’s observations, SEXTANT created an on-board navigation system using NICER’s pulsar data. It worked by measuring the consistent timing between each pulsar’s pulses to map a set of cosmic beacons.
When calculating position or location, extremely accurate timekeeping is essential. We usually rely on atomic clocks, which use the predictable fluctuations of atoms to tick away the seconds. These atomic clocks can be located on the ground or in space, like the ones on GPS satellites. However, our GPS system only works on or close to Earth, and onboard atomic clocks can be expensive and heavy. Using pulsar observations instead could give us free and reliable “clocks” for navigation. During its experiment, SEXTANT was able to successfully determine the space station’s orbital position!
We can calculate distances using the time taken for a signal to travel between two objects to determine a spacecraft’s approximate location relative to those objects. However, we would need to observe more pulsars to pinpoint a more exact location of a spacecraft. As SEXTANT gathered signals from multiple pulsars, it could more accurately derive its position in space.
So, imagine you are an astronaut on a lengthy journey to the outer solar system. You could use the technology developed by SEXTANT to help plot your course. Since pulsars are reliable and consistent in their spins, you wouldn’t need Wi-Fi or cell service to figure out where you were in relation to your destination. The pulsar-based navigation data could even help you figure out your ETA!
None of these missions or experiments would be possible without Jocelyn Bell Burnell’s keen eye for an odd spot in her radio data decades ago, which set the stage for the idea to use spinning neutron stars as a celestial GPS. Her contribution to the field of astrophysics laid the groundwork for research benefitting the people of the future, who yearn to sail amongst the stars.
Keep up with the latest NICER news by following NASA Universe on X and Facebook and check out the mission’s website. For more on space navigation, follow @NASASCaN on X or visit NASA’s Space Communications and Navigation website.
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On Tuesday, April 4 at 3 p.m. EDT (noon PDT), At Jet Propulsion Laboratory, the Cassini team host a news briefing to discuss the mission's Grand Finale.
Tune in Tuesday: youtube.com/nasajpl/live
Cassini left Earth with less than 1/30th of the propellant needed to power all her adventures at Saturn. The navigation team used the gravity of Saturn's giant moon Titan to change course and extend the spacecraft's exploration of Saturn. Titan also provides the gravity assist to push Cassini into its final orbits.
More on Cassini's navigation: saturn.jpl.nasa.gov/mission/spacecraft/navigation/
Cassini is an orbiter that was named for 18th century astronomer Giovanni Domenico Cassini. She was designed to be captured by Saturn's gravity and then explore it in detail with a suite of 12 powerful science instruments.
More on the Spacecraft: saturn.jpl.nasa.gov/mission/spacecraft/cassini-orbiter/
Cassini carried the European Space Agency's Huygens Probe, which in 2005 descended through Titan's thick, perpetual clouds and made the most distant landing to date in our solar system.
More on Huygens: saturn.jpl.nasa.gov/mission/spacecraft/huygens-probe/
Your mobile phone likely captures dozens of megapixels in images. Cassini, using 1990s technology closer to one megapixel cameras, has returned some of the most stunning images in the history of solar system exploration.
Cassini Hall of Fame Images: go.nasa.gov/2oec6H2 More on Cassini's Cameras: saturn.jpl.nasa.gov/imaging-science-subsystem/
Those great images have inspired artist's and amateur image processors to create truly fantastic imagery inspired by the beauty of Saturn. Feeling inspired? There's still time to share your Cassini-inspired art with us.
Cassini Inspires Campaign: saturn.jpl.nasa.gov/mission/cassiniinspires/
Two decades is a long time to live in the harsh environment of outer space (respect to the fast-approaching 40-year-old twin Voyager spacecraft). Launched in 1997, Cassini logged a lot of milestones over the years.
Explore the Cassini Timeline: saturn.jpl.nasa.gov/the-journey/timeline/
And, you can read it. Week after week going back to 1997, Cassini's adventures, discoveries and status have been chronicled in the mission's weekly significant events report.
Read It: https://saturn.jpl.nasa.gov/news/?topic=121
Cassini was the prototype for NASA's Eyes on the Solar System 3-D visualization software, so it's fitting the latest Cassini module in the free, downloadable software is the most detailed, elaborate visualization of any mission to date.
Fly the Mission - Start to Finish: http://eyes.nasa.gov/cassini
In addition to all the new information from 22 orbits in unexplored space, Cassini's engineers reprogrammed the spacecraft to send back details about Saturn's atmosphere to the very last second before the giant planet swallows her up on Sept. 15, 2017.
More on the Grand Finale: saturn.jpl.nasa.gov/grandfinale
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We’re not just doing research in space! From the land, the sea and the sky, we study our planet up close. Right now, we’re gearing up for our newest round of Earth Expeditions, using planes, boats and instruments on the ground to study Earth and how it’s changing.
The newest round of campaigns takes place all across the United States – from Virginia to Louisiana to Kansas to California.
The five newest missions will combine measurements from the ground, the sea, air and space to investigate storms, sea level rise and processes in the atmosphere and ocean.
Let’s meet the newest Earth science missions:
The Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms will start from Wallops Flight Facility in Virginia to understand how bands of snow form during winter storms in the East Coast. This research will help us better forecast intense snowfall during extreme winter weather.
Flying out of Langley Research Center, the Aerosol Cloud Meteorology Interactions over the Western Atlantic Experiment is studying how specific types of clouds over oceans affect Earth’s energy balance and water cycle. The energy balance is the exchange of heat and light from the Sun entering Earth’s atmosphere vs. what escapes back into space.
Farther south, Delta-X is flying three planes around the Mississippi River Delta to study how land is deposited and maintained by natural processes. Studying these processes can help us understand what will happen as sea levels continue to rise.
Heading out to the Midwest this summer, the Dynamics and Chemistry of the Summer Stratosphere mission will study how thunderstorms can carry pollutants from high in the atmosphere deep into the lower stratosphere, where they can affect ozone levels.
About 200 miles off the coast of San Francisco, the Sub-Mesoscale Ocean Dynamics Experiment is using ships, planes and gliders to study the impact that ocean eddies have on how heat moves between the ocean and the atmosphere.
These missions are kicking off in January, so stay tuned for our updates from the field! You can follow along with NASA Expeditions on Twitter and Facebook.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
What does a normal day for you consist of?
After years of preparatory studies, we are formally starting an astrophysics mission designed to help unlock the secrets of the universe.
With a view 100 times bigger than that of our Hubble Space Telescope, WFIRST will help unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It will also help us discover new worlds and advance the search for planets suitable for life.
WFIRST is slated to launch in the mid-2020s. The observatory will begin operations after traveling about one million miles from Earth, in a direction directly opposite the sun.
Telescopes usually come in two different “flavors” - you have really big, powerful telescopes, but those telescopes only see a tiny part of the sky. Or, telescopes are smaller and so they lack that power, but they can see big parts of the sky. WFIRST is the best of worlds.
No matter how good a telescope you build, it’s always going to have some residual errors. WFIRST will be the first time that we’re going to fly an instrument that contains special mirrors that will allow us to correct for errors in the telescope. This has never been done in space before!
Employing multiple techniques, astronomers will also use WFIRST to track how dark energy and dark matter have affected the evolution of our universe. Dark energy is a mysterious, negative pressure that has been speeding up the expansion of the universe. Dark matter is invisible material that makes up most of the matter in our universe.
Single WFIRST images will contain over a million galaxies! We can’t categorize and catalogue those galaxies on our own, which is where citizen science comes in. This allows interested people in the general public to solve scientific problems.
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Believe it or not, the International Space Station is paving our way to Mars. Being the only microgravity laboratory in which long-duration investigations can take place, it provides deeper understanding of how the human body reacts to long-term spaceflight. Here are the top 10 ways the space station is helping us on our journey to the Red Planet:
10: Communication Delays
Have you ever sent a text and got frustrated when it took longer than 3 seconds to send? Imaging communicating from Mars where round-trip delays could take up to 31 minutes! Our Comm Delay Assessment studies the effects of delayed communications for interplanetary crews that have to handle medical and other emergencies in deep space.
9. Astronaut Functional Performance
After a long nights sleep, do you ever feel a bit clumsy when you first get out of bed? Imagine how crew members might feel after spending six months to a year in microgravity! Our Field Test investigation is working to understand the extend of physical changes in astronauts who live in space for long periods of time, with an aim toward improving recovery time and developing injury prevention methods for future missions.
8. Psychological Impacts of Isolation and Confinement
In order to study the behavioral issues associated with isolation and confinement, researchers evaluate the personal journals of space station crew members. These study results provide information to help prepare us for longer duration spaceflight.
7. Impacts on Vision
Did you know that long duration spaceflight can often cause changes to crew members’ vision? It can, and our Ocular Health study monitors microgravity-induced visual impairment, as well as changes believed to arise from elevated intracranial pressure. All of this work hopes to characterize how living in microgravity can affect the visual, vascular and central nervous systems.
6. Immune Responses
An important aspect of our journey to Mars is the need to understand how long-duration spaceflight affects they way crew members’ bodies defend agains pathogens. Our Integrated Immune investigation collects and analyzes blood, urine and saliva samples from crew members before, during and after spaceflight to monitor changes in the immune system.
5. Food for Long-Duration Crews
Just like a hiker preparing for a long trek, packing the foods that will give you the most energy for the longest amount of time is key to your success. This is also true for astronauts on long-duration missions. Our Energy investigation measures a crew members’ energy requirements, which is a crucial factor needed for sending the correct amount of the right types of food to space.
4. Exercise for Long-Term Missions
Rigorous exercise is already a regular part of astronauts’ routines, and continuing that focus will be critical to keeping crew members’ bodies strong and ready for a mission to Mars and a healthy return to Earth. Our Sprint investigation is studying the best combination of intensity and duration for exercise in space.
3. Determine Best Habitat/Environment for Crews
Have you ever complained about your room being too small? Imagine living in cramped quarters with an entire crew for months on a Mars mission! Our Habitability investigation collects observations that will help spacecraft designers understand how much habitable volume is required, and whether a mission’s duration impacts how much space crew members need.
2. Growing Food in Space
There’s nothing like fresh food. Not only does it provide valuable nutrition for astronauts, but can also offer psychological benefits from tending and harvesting the crops. Our Veggie investigation studies how to best utilize a facility aboard the space station for growing fresh produce in microgravity.
1. Manufacturing Items in Space
When crews head to Mars, there may be items that are unanticipated or that break during the mission. Our 3-D Printing in Zero-G Technology Demonstration would give crews the ability to manufacture new objects on demand while in space.
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