Published by NASA
Link to article with video: https://www.jpl.nasa.gov/video/details.php?id=1588
Link to page: International Observe the Moon Night, Oct 5, 2019
What can you see in the October sky? Join the global celebration of International Observe the Moon Night on Oct. 5th, then try to catch the ice giant planets Uranus and Neptune, which are well placed for viewing in the late night sky.
What’s Up for October? A night for the whole world to observe the Moon and hunting for ice giants!
International Observe the Moon Night is Oct. 5th. It’s an annual celebration of lunar observation and exploration. Events are scheduled in lots of places around the world, so there may be one near you. But all you really need to participate is to go out and look up.
The event is timed to coincide with the first quarter moon. This allows for some great observing along the lunar terminator – the line that divides the dayside from the nightside. With even a small pair of binoculars, you can see some great details as features like mountains and craters pop up into the light. Learn more and look for events in your area at moon.nasa.gov/observe.
October is a great time to try and capture an ICE GIANT. Now, these aren’t mythical creatures. They’re planets – the most distant of the major planets of our solar system, Uranus and Neptune.
The four giant planets of our solar system are not created equal. The gas giants, Jupiter and Saturn, are much bigger and way more massive, while the ice giants are so named because they contain a much higher amount of materials that typically form ices in the frigid depths of the outer solar system.
In October, both Uranus and Neptune are well placed in the late night sky. In fact, you can see all four giant planets in the same evening if you look for Jupiter and Saturn in the west after sunset, and then come back a couple of hours later to spot Uranus and Neptune. (Think of it as your own personal “Voyager mission.” NASA’s Voyager 2 is the only spacecraft to have visited the ice giants so far, although scientists are eager to go back for a more detailed study.)
Unlike Jupiter and Saturn, the ice giants are quite faint, so the best way to observe them is with a telescope, and from personal experience, it’s much easier to find them if you have a computer-controlled mount that can automatically point the telescope for you. If you don’t have access to one, find a local event with the Night Sky Network at nightsky.jpl.nasa.gov. Otherwise, sky watching apps can help you star-hop your way to these two incredibly distant planets.
Now be advised, because they’re so far away, each planet appears as just a point of light. But with a modest telescope, you’ll see Uranus as a tiny disk. You’d be forgiven for mistaking Neptune as a star – it’s the same size as Uranus, but much farther away, so it’s fainter.
The ice giants are elusive, but well worth the effort to say you’ve seen them with your own eyes.
Here are the phases of the Moon for October. You can catch up on all of NASA’s current and future missions at nasa.gov. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
Martian weather and soil conditions that NASA’s Curiosity rover has measured, together with a type of salt found in Martian soil, could put liquid brine in the soil at night.
Perchlorate identified in Martian soil by the Curiosity mission, and previously by NASA’s Phoenix Mars Lander mission, has properties of absorbing water vapor from the atmosphere and lowering the freezing temperature of water. This has been proposed for years as a mechanism for possible existence of transient liquid brines at higher latitudes on modern Mars, despite the Red Planet’s cold and dry conditions.
New calculations were based on more than a full Mars year of temperature and humidity measurements by Curiosity. They indicate that conditions at the rover’s near-equatorial location were favorable for small quantities of brine to form during some nights throughout the year, drying out again after sunrise. Conditions should be even more favorable at higher latitudes, where colder temperatures and more water vapor can result in higher relative humidity more often.
“Liquid water is a requirement for life as we know it, and a target for Mars exploration missions,” said the report’s lead author, Javier Martin-Torres of the Spanish Research Council, Spain, and Lulea University of Technology, Sweden, and a member of Curiosity’s science team. “Conditions near the surface of present-day Mars are hardly favorable for microbial life as we know it, but the possibility for liquid brines on Mars has wider implications for habitability and geological water-related processes.”
- Conditions that might produce liquid brine in Martian soil extend closer to the equator than expected
- Perchlorate salt in soil can pull water molecules from the atmosphere and act as anti-freeze
- Presence of brine would not make Curiosity’s vicinity favorable for microbes
The weather data in the report published today in Nature Geosciences come from the Cuirosity’s Rover Environmental Monitoring Station (REMS), which was provided by Spain and includes a relative-humidity sensor and a ground-temperature sensor. NASA’s Mars Science Laboratory Project is using Curiosity to investigate both ancient and modern environmental conditions in Mars’ Gale Crater region. The report also draws on measurements of hydrogen in the ground by the rover’s Dynamic Albedo of Neutrons (DAN) instrument, from Russia.
“We have not detected brines, but calculating the possibility that they might exist in Gale Crater during some nights testifies to the value of the round-the-clock and year-round measurements REMS is providing,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, Pasadena, California, one of the new report’s co-authors.
Curiosity is the first mission to measure relative humidity in the Martian atmosphere close to the surface and ground temperature through all times of day and all seasons of the Martian year. Relative humidity depends on the temperature of the air, as well as the amount of water vapor in it. Curiosity’s measurements of relative humidity range from about five percent on summer afternoons to 100 percent on autumn and winter nights.
Air filling pores in the soil interacts with air just above the ground. When its relative humidity gets above a threshold level, salts can absorb enough water molecules to become dissolved in liquid, a process called deliquescence. Perchlorate salts are especially good at this. Since perchlorate has been identified both at near-polar and near-equatorial sites, it may be present in soils all over the planet.
Researchers using the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter have in recent years documented numerous sites on Mars where dark flows appear and extend on slopes during warm seasons. These features are called recurring slope lineae, or RSL. A leading hypothesis for how they occur involves brines formed by deliquesence.
“Gale Crater is one of the least likely places on Mars to have conditions for brines to form, compared to sites at higher latitudes or with more shading. So if brines can exist there, that strengthens the case they could form and persist even longer at many other locations, perhaps enough to explain RSL activity,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson, also a co-author of the new report.
In the 12 months following its August 2012 landing, Curiosity found evidence for ancient streambeds and a lakebed environment more than 3 billion years ago that offered conditions favorable for microbial life. Now, the rover is examining a layered mountain inside Gale Crater for evidence about how ancient environmental conditions evolved. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory and Mars Reconnaissance Projects for NASA’s Science Mission Directorate, Washington.
For more information about Curiosity, visit: