The best celestial show of the year is taking place right now, with the Perseid meteor shower peaking from August 11 to 13.
A Perseid meteor as seen in Greece (Babak A. Tafreshi/ TWAN/ National Geographic).
The event occurs when Earth passes through a stream of fragments left by a comet. The particles, ranging in size from small grains to boulders, collide with Earth’s atmosphere at 100,000 miles per hour. This result is what is referred to as a shooting star.
“As the Earth passes through the dust trail of comets, it encounters debris—some of which can be the size of grapefruit or larger—which [then] can cause fireballs,” Raminder Singh Samra, resident astronomer at the H.R. MacMillan Space Centre in Vancouver, British Columbia, said.
“The chances of seeing fireballs always increase when there is a strong meteor shower like this one,” he added.
The Perseids should be especially visible this year due to the waxing crescent moon setting earlier than usual. The shower will be mostly visible from the northern hemisphere and is best seen in the northeast sky. With dark conditions, expect to see between 60 and 100 meteors per hour.
NASA is stepping up its efforts to monitor forest fires, in wake of the recent Black Forest wildfires in Colorado, which destroyed 500 homes in 48 hours and killed two people.
False-color image of the Black Forest burn scar as seen from NASA’s Terra satellite (NASA’s Earth Observatory).
The administration’s effort involves the use of “fire towers,” which are satellites it plans to use to give wildlife monitoring agencies the most up-to-date information possible.
“For more than a decade, instruments on Terra and Aqua, two of NASA’s flagship Earth-observing satellites, have scanned the surface of our planet for fires,” NASA said in a news release. “An instrument on both satellites, the Moderate Resolution Imaging Spectroradiometer (MODIS), has revolutionized what scientists know about fire’s role in land cover change, ecosystem processes and the global carbon cycle by allowing researchers to map characteristics of the global distribution of fires in remarkable detail.”
There are currently two active MODIS sensors which orbit the globe every 99 minutes. Captured information is sent to Earth via text message, and agencies including the U.S. Forest Service respond accordingly.
NASA/NOAA Suomi National Polar-orbiting Partnership also launched Visible Infrared Imaging Radiometer Suite (VIIRS), another satellite which provides two additional daily observations. Fire scientists also use Landfire (Landscape Fire and Resources Management Planning Tools project), which culls data from NASA and U.S. Geological Survey-operated Landsat satellites.
Check out this video from NASA on forest fires and data collection.
Archaeologists have made a big discovery in Guatemala, uncovering a Mayan frieze over 1,400 years old.
The frieze was discovered in the Maya city of Holmul in the Peten region of Guatemala. It measures 26 feet by almost seven feet and depicts humans in a mythological setting. This suggests that those portrayed may be deified rulers.
The find was made by Archaeologist Francisco Estrada-Belli and his team as they were investigating a tunnel left open by looters. The frieze is 95 percent preserved, which is quite high for an archaeological find. Traces of red, blue, green and yellow paint still adorn the surface.
“It gives you an idea of how intricate and ornate these sites that we are excavating must have been during their apogee,” archaeologist Marcello Canuto said. “These sites must have been a feast for the eyes when they were inhabited.”
The frieze was found in a section of the temple dating back to A.D. 590. This is known as the Maya classical era. During this time, two major dynasties battled for control of the Maya: Tikal and Kaanul. An inscription indicates that the frieze, and therefore the city of Holmul, belonged to the Kaanul kingdom.
Such finds indicate that Holmul, despite being small, was a city of major importance for these dynasties, perhaps due to access to nearby riches including basalt, obsidian and jade.
The frieze is too big to move, so for now it is staying put.
“We’re going to try to preserve it and create a stable environment around it so people can eventually visit it,” Estrada-Belli said.
NASA has its eyes set on alien life, but it’s not looking for Martians. Rather, a new report details the administration’s plans for landing on and exploring Jupiter’s moon Europa.
According to a new study published in the journal Astrobiology, a NASA-appointed “science-definition team” wants to determine the thickness and dynamics of the moon’s ice shell, as well as its surface geology and the composition of its vast, cold ocean lying below its icy surface.
Artist’s conception of a view of Jupiter from Europa (NASA/JPL-Caltech)
“If one day humans send a robotic lander to the surface of Europa, we need to know what to look for and what tools it should carry,” study lead author Robert Pappalardo of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. said in a statement.
“There is still a lot of preparation that is needed before we could land on Europa, but studies like these will help us focus on the technologies required to get us there, and on the data needed to help us scout out possible landing locations,” he added.
Pappalardo and his colleagues suggest that a landing module be capable of drilling four inches into Europa’s surface. Though astrobiologists would love to land a module on Europa, no such plans currently exist from NASA. The European Space Agency is launching a mission titled JUICE (JUpiter ICy moons Explorer), which will include launching a probe toward Jupiter in 2022. After arriving in 2030, the spacecraft would spend three years studying Jupiter, Europa and the moons Callisto and Ganymede. It would not, however, land on any of these worlds.
The sun is about to undergo a major flip.
According to NASA, the sun’s magnetic field will undergo a change in a matter of months that takes place once every 11 years. As the sun’s magnetic field flips, it reaches the peak of its solar cycle and the halfway point of its “solar maximum.”
Stormy space weather could result, NASA states.
“It looks like we’re no more than three to four months away from a complete field reversal,” Todd Hoeksema, the director of Stanford University’s Wilcox Solar Observatory, said in a statement. “This change will have ripple effects throughout the solar system.”
However, the solar transition also provides additional shielding form dangerous cosmic rays, such as those accelerated from distant supernovas.
Scientists from the Georgia Institute of Technology have succeeded in replicating the Mona Lisa on the world’s smallest canvas.
Georgia Institute of Technology
The canvas is about 30 microns in width, about one third the size of a human hair. To replicate the image, the researchers used ThermoChemical NanoLithography (TCNL) to create chemical reactions resulting from heat. More heat produced lighter shades of gray, while less heat produced darker shades.
According to researchers, the technique could one day be used to nanomanufacture devices.
“We envision TCNL will be capable of patterning gradients of other physical or chemical properties, such as conductivity of graphene,” physics professor Jennifer Curtis said. “This technique should enable a wide range of previously inaccessible experiments and applications in fields as diverse as nanoelectronics, optoelectronics and bioengineering.”
The origin of chemical elements like gold could be explained by mergers between neutron stars and black holes, scientists claim.
Stellar merger model for gamma-ray burst (NASA).
The find is based on observations made last month by NASA’s Hubble Space Telescope, which detected a gamma ray burst (GRB) accompanying a stellar explosion called a kilonova.
“Many astronomers, including our group, have already provided a great deal of evidence that long-duration gamma ray bursts (those lasting more than two seconds) are produced by the collapse of extremely massive stars,” study lead author Nial Tanvir of the University of Leicester in the United Kingdom said in a statement. “But we only had weak circumstantial evidence that short bursts were produced by the merger of compact objects. This result now appears to provide definitive proof supporting that scenario.”
Because of the discovery, scientists hope to gain a clearer understanding of the origin of heavy metals. They believe that kilonovas produce a large amount of such elements, launching them into space where they become part of future planets and stars.