Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. Your tax dollars help promote science! The following article was provided for reprinting by the Night Sky Network in August, 2019.
Is the summer heat getting to you? Cool off overnight while spotting one of the solar system’s ice giants: Neptune! It’s the perfect way to commemorate the 30th anniversary of Voyager 2’s flyby.
Neptune is too dim to see with your unaided eye so you’ll need a telescope to find it. Neptune is at opposition in September, but its brightness and apparent size won’t change dramatically as it’s so distant; the planet is usually just under 8th magnitude and 4.5 billion kilometers away. You can see Neptune with binoculars but a telescope is recommended if you want to discern its disc; the distant world reveals a very small but discernible disc at high magnification. Neptune currently appears in Aquarius, a constellation lacking in bright stars, which adds difficulty to pinpointing its exact location. Fortunately, the Moon travels past Neptune the night of August 16th, passing less than six degrees apart (or about 12 Moon widths) at their closest. If the Moon’s glare overwhelms Neptune’s dim light, you can still use the its location that evening to mark the general area to search on a darker night. Another Neptune-spotting tip: Draw an imaginary line from bright southern star Fomalhaut up to the Great Square of Pegasus, then mark a point roughly in the middle and search there, in the eastern edge of Aquarius. If you spot a blue-ish star, swap your telescope’s eyepiece to zoom in as much as possible. Is the suspect blue “star” now a tiny disc, while the surrounding stars remain points of white light? You’ve found Neptune!
Neptune and Uranus are ice giant planets. These worlds are larger than terrestrial worlds like Earth but smaller than gas giants like Jupiter. Neptune’s atmosphere contains hydrogen and helium like a gas giant, but also methane, which gives it a striking blue color. The “ice” in “ice giant” refers to the mix of ammonia, methane, and water that makes up most of Neptune’s mass, located in the planet’s large, dense, hot mantle. This mantle surrounds an Earth-size rocky core. Neptune possesses a faint ring system and 13 confirmed moons. NASA’s Voyager 2 mission made a very close flyby on August 25, 1989. It revealed a dynamic, stormy world streaked by the fastest winds in the solar system, their ferocity fueled by the planet’s surprisingly strong internal heating. Triton, Neptune’s largest moon, was discovered to be geologically active, with cryovolcanoes erupting nitrogen gas and dust dotting its surface, and a mottled “cantaloupe” terrain made up of hard water ice. Triton is similar to Pluto in size and composition, and orbits Neptune in the opposite direction of the planet’s rotation, unlike every other large moon in the solar system. These clues lead scientists to conclude that this unusual moon is likely a captured Kuiper Belt object.
Discover more about Voyager 2, along with all of
NASA’s past, present, and future missions, at nasa.gov
Clockwise from top left: Neptune and the Great Dark Spot traced by white clouds; Neptune’s rings; Triton and its famed icy cantaloupe surface; close of up Triton’s surface, with dark streaks indicating possible cyrovolcano activity. Find more images and science from Voyager 2’s flyby at bit.ly/NeptuneVoyager2Image Credit: NASA/JPLFinder chart for Neptune. This is a simulated view through 10×50 binoculars (10x magnification). Please note that the sizes of stars in this chart indicate their brightness, not their actual size. Moon image courtesy NASA Scientific Visualization Studio; chart created with assistance from Stellarium.
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The NASA News Service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these announcements from NASA can subscribe to their service by sending an email to: hqnews-request@newsletters.nasa.gov?subject=subscribe
Be An Astronaut: NASA Seeks Explorers For Future Space Missions
In anticipation of returning human spaceflight launches to American soil, and in preparation for the agency’s journey to Mars, NASA announced it will soon begin accepting applications for the next class of astronaut candidates. With more human spacecraft in development in the United States today than at any other time in history, future astronauts will launch once again from the Space Coast of Florida on American-made commercial spacecraft, and carry out deep-space exploration missions that will advance a future human mission to Mars.
The agency will accept applications from Dec. 14 through mid-February and expects to announce candidates selected in mid-2017. Applications for consideration as a NASA Astronaut will be accepted at: http://www.usajobs.gov
The next class of astronauts may fly on any of four different U.S. vessels during their careers: the International Space Station, two commercial crew spacecraft currently in development by U.S. companies, and NASA’s Orion deep-space exploration vehicle.
From pilots and engineers, to scientists and medical doctors, NASA selects qualified astronaut candidates from a diverse pool of U.S. citizens with a wide variety of backgrounds.
The agency will accept applications from Dec. 14 through mid-February and expects to announce candidates selected in mid-2017. Applications for consideration as a NASA Astronaut will be accepted at:
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For more information about a career as a NASA astronaut, and application requirements, visit: www.nasa.gov/astronauts
NASA Mission Reveals Speed of Solar Wind Stripping Martian Atmosphere
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today.
MAVEN data have enabled researchers to determine the rate at which the Martian atmosphere currently is losing gas to space via stripping by the solar wind. The findings reveal that the erosion of Mars’ atmosphere increases significantly during solar storms. The scientific results from the mission appear in the Nov. 5 issues of the journals Science and Geophysical Research Letters.
“Mars appears to have had a thick atmosphere warm enough to support liquid water which is a key ingredient and medium for life as we currently know it,” said John Grunsfeld, astronaut and associate administrator for the NASA Science Mission Directorate in Washington. “Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere. Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in NASA’s journey to Mars.”
From possible ice volcanoes to twirling moons, NASA’s New Horizons science team is discussing more than 50 exciting discoveries about Pluto at this week’s 47th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences in National Harbor, Maryland.
“The New Horizons mission has taken what we thought we knew about Pluto and turned it upside down,” said Jim Green, director of planetary science at NASA Headquarters in Washington. “It’s why we explore — to satisfy our innate curiosity and answer deeper questions about how we got here and what lies beyond the next horizon.”
For one such discovery, New Horizons geologists combined images of Pluto’s surface to make 3-D maps that indicate two of Pluto’s most distinctive mountains could be cryovolcanoes — ice volcanoes that may have been active in the recent geological past.
During a noon EST media teleconference today, NASA and university scientists will discuss new insights, tools and agency research into key carbon and climate change questions, as the agency ramps up its efforts to understand how Earth’s ocean, forest, and land ecosystems absorb nearly half of emitted carbon dioxide today.
Carbon dioxide emitted into the atmosphere by human activities influences the amount of the sun’s energy trapped by Earth’s atmosphere. These emissions are the subject of a United Nations climate conference in Paris later this month. To improve the information available to policymakers on this issue, scientists are grappling with the complex question of whether Earth’s oceans, forests and land ecosystems will maintain their capacity to absorb about half of all human-produced carbon dioxide emissions in the future.
“NASA is at the forefront of scientific understanding in this area, bringing together advanced measurement technologies, focused field experiments, and cutting-edge research to reveal how carbon moves around the planet and changes our climate,” said Michael Freilich, director of NASA’s Earth Science Division. “Understanding how the planet responds to human carbon emissions and increasing atmospheric CO2 levels will position our nation to take advantage of the opportunities and face the challenges that climate changes present.”
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To learn more about NASA’s efforts to better understand the carbon and climate challenge, visit: www.nasa.gov/carbonclimate
NASA Orders SpaceX Crew Mission To International Space Station
NASA took a significant step Friday toward expanding research opportunities aboard the International Space Station with its first mission order from Hawthorne, California based-company SpaceX to launch astronauts from U.S. soil.
This is the second in a series of four guaranteed orders NASA will make under the Commercial Crew Transportation Capability (CCtCap) contracts. The Boeing Company of Houston received its first crew mission order in May.
“It’s really exciting to see SpaceX and Boeing with hardware in flow for their first crew rotation missions,” said Kathy Lueders, manager of NASA’s Commercial Crew Program. “It is important to have at least two healthy and robust capabilities from U.S. companies to deliver crew and critical scientific experiments from American soil to the space station throughout its lifespan.”
