SOFIE resumed science measurements on November 21, 2017, when the AIM orbit beta angle became low enough (below ~67 degrees) to enable solar occultation to be viewed from orbit. These observations are in the Northern winter and feature nearly co-located sunrise and sunset measurements, that will be used in investigations of the mesospheric vortex. continue ->
in the Mesosphere (AIM) satellite mission is exploring Polar Mesospheric Clouds
(PMCs), also called noctilucent clouds, to find out why they
form and why they are changing.
The AIM mission was launced in 2007 and has been extended by NASA through the end of FY15. During this time the
instruments monitor noctilucent clouds to better understand
their variability and possible connection to climate change.
Individual instrument data collection status, as well as spacecraft
and instrument health, will be monitored throughout the life
of the mission and reported periodically on this website.
The primary goal of the AIM mission is to help scientists understand whether the clouds' ephemeral nature, and their variation over time, is related to Earth's changing climate - and to investigate why they form in the first place. By measuring the thermal, chemical and other properties of the environment in which the mysterious clouds form, the AIM mission will provide researchers with a foundation for the study of long-term variations in the mesosphere and its relationship to global climate change. In addition to measuring environmental conditions, the AIM mission will collect data on cloud abundance, how the clouds are distributed, and the size of particles within them.
Glowing silver-blue clouds that sometimes light up summer night skies at high latitudes, after sunset and before sunrise, are called noctilucent clouds. Also known as night shining clouds, they form in the highest reaches of the atmosphere – the mesosphere – as much as 50 miles (80 km) above the Earth’s surface. They’re seen during summer in polar regions. They’re typically seen between about 45° and 60° latitude, from May through August in the Northern Hemisphere or November through February in the Southern Hemisphere.
Noctilucent clouds are thought to be made of ice crystals that form on fine dust particles from meteors. They can only form when temperatures are incredibly low and when there’s water available to form ice crystals.
Why do these clouds – which require such cold temperatures – form in the summer?
Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud. Although noctilucent clouds appear most often at arctic latitudes, they have been sighted in recent years as far south as Colorado, Utah and Virginia. NLCs are seasonal, appearing most often in late spring and summer. In the northern hemisphere, the best time to look would be between mid-May and the end of August.
SOFIE returned to science measurements in October 2018, when the AIM orbit propagated to sufficiently low beta angles. The orbit is now reversed in direction compared to the previous ~12 years, so that SOFIE spacecraft sunset (sunrise) now occurs in the Northern (Southern) Hemisphere. SOFIE science and housekeeping parameters all indicate a stable and healthy instrument. SOFIE V1.3 data are available online.
Noctilucent (“night-shining”) cloud over Antarctica in early January, 2018, from NASA’s AIM satellite.
The sky over Antarctica is now glowing electric blue with noctilucent, or night-shining, clouds. That’s according to recent images from NASA’s AIM spacecraft (Aeronomy of Ice in the Mesosphere), which monitors these clouds for the whole Earth. Read more ->
NASA's AIM spacecraft is back in business. Following a months-long interruption in normal operations, the polar-orbiting satellite is beaming back new images of noctilucent clouds at the edge of space. Data arriving now show a magnificent ring of electric-blue surrounding Earth's north pole, confirming recent sightings from the surface of our planet. Visit today's edition of Spaceweather.com to learn more about these strange clouds and the status of AIM.
NLCs are, essentially, clouds of frosted meteor smoke. They form when wisps of summertime water vapor rise toward the top of Earth's atmosphere. Water molecules stick to the microscopic debris of disintegrated meteoroids, assembling themselves into tiny crystals of ice that glow beautifully in sunlight at the edge of space.
Above: Noctilucent clouds surround Earth's north pole in this July 24th image from NASA's AIM spacecraft.
After delayed start, magnificent noctilucent clouds are back in full effectDate: July 04, 2017
NASA’s AIM Observes Early Noctilucent Ice Clouds Over Antarctica Date: December 2, 2016 www.nasa.gov
Data from NASA’s Aeronomy of Ice in the Mesosphere, or AIM, spacecraft shows the sky over Antarctica is glowing electric blue due to the start of noctilucent, or night-shining, cloud season in the Southern Hemisphere. This data was collected from Nov. 17-28, 2016.