Astronomers Find a Moon Hiding Around Makemake in Hubble Data

Dwarf planet Makemake and its newly discovered moon.
The newly discovered moon, MK 2, found in Hubble data orbiting Makemake.
NASA, ESA, A. Parker
In 2005, Caltech astronomers Mike Brown and Chad Trujillo discovered dwarf planet Makemake, currently believed to be the third largest object in the Kuiper Belt after Pluto and Eris. But at the time, astronomers believed it was alone out there on its long path around the Sun. But new data from the Hubble Space Telescope reveal a moon around the tiny world, and offer a little explanation as to where it was hiding.
“The satellite that we found was not that faint and not that close to Makemake,” says Alex Parker, principal investigator of the research and a planetary scientist at the Southwest Research Institute. “It popped right out of the data when we looked.”
It turns out it was always there. But the newly found object, provisionally called MK 2, orbits Makemake nearly edge-on from our point of view, meaning most of the time it’s obscured by the comparatively bright dwarf planet. Makemake is 886 miles (1,434 km) in diameter, while the new object appears to be only 100 miles (161 Km). Current scenarios also paint it as a dark companion compared to bright Makemake.
The dark surface of MK 2, which in one scenario may reflect as little as 4 percent of light, could explain why astronomers previously showed Makemake to have two highly contrasting albedos (reflectivities) that indicated different materials at work. Those dark spots didn’t seem to line up with the 7.7-hour day on Makemake, though.
“You would expect Makemake’s brightness would go up and down as it rotated, but it’s brightness hardly goes up or down,” Parker says.
There are two possibilities for why a bright dwarf planet has such a dark moon. In one scenario, it’s a captured Kuiper Belt Object that through various circumstances ended up in orbit around Makemake. In the other, a collision formed it, much like the one that formed Pluto’s moon system.
In the latter scenario, Makemake may have a sort of seasonal atmosphere, and as the ices and other chemicals on its surface sublimate, it covers MK 2 in a hydrocarbon film known as tholin. This same process likely creates the red patches on Pluto’s moon Charon’s north pole.
“You might imagine you could paint this moon dark with a transitory Makemake-ian atmosphere,” Parker says.
Follow-up observations will help determine an orbit for MK 2, something that may be hard given its edge-on nature. This would give the researchers a chance to study the size of the moon and help determine a mass for Makemake, especially if they can predict the intervals at which it is visible. In the meantime, Makemake joins a short list of Kuiper Belt Objects known to have moons, including Pluto, Eris, Quaoar, and Haumea.

A pre-print of the paper is available here
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New closeup Ceres images show bright craters in amazing detail (video)

Ceres’ Haulani Crater, with a diameter of 21 miles (34 kilometres), shows evidence of landslides from its crater rim and rays of bluish ejected material in this enhanced false-colour view. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Craters with bright material on dwarf planet Ceres shine in new images from NASA’s Dawn mission.
In its lowest-altitude mapping orbit, at a distance of 240 miles (385 kilometres) from Ceres, Dawn has provided scientists with spectacular views of the dwarf planet.
Haulani Crater, with a diameter of 21 miles (34 kilometres), shows evidence of landslides from its crater rim. Smooth material and a central ridge stand out on its floor. An enhanced false-colour view allows scientists to gain insight into materials and how they relate to surface morphology. This image shows rays of bluish ejected material. The colour blue in such views has been associated with young features on Ceres.
“Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in colour from older parts of the surface,” said Martin Hoffmann, co-investigator on the Dawn framing camera team, based at the Max Planck Institute for Solar System Research, Göttingen, Germany.
The crater’s polygonal nature (meaning it resembles a shape made of straight lines) is noteworthy because most craters seen on other planetary bodies, including Earth, are nearly circular. The straight edges of some Cerean craters, including Haulani, result from pre-existing stress patterns and faults beneath the surface.



Six-mile-wide (10-kilometre-wide) Oxo Crater is unique because of the relatively large "slump" in its crater rim. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.Six-mile-wide (10-kilometre-wide) Oxo Crater is unique because of the relatively large “slump” in its crater rim. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.
A hidden treasure on Ceres is the 6-mile-wide (10-kilometre-wide) Oxo Crater, which is the second-brightest feature on Ceres (only Occator’s central area is brighter). Oxo lies near the 0 degree meridian that defines the edge of many Ceres maps, making this small feature easy to overlook. Oxo is also unique because of the relatively large “slump” in its crater rim, where a mass of material has dropped below the surface. Dawn science team members are also examining the signatures of minerals on the crater floor, which appear different than elsewhere on Ceres.
“Little Oxo may be poised to make a big contribution to understanding the upper crust of Ceres,” said Chris Russell, principal investigator of the mission, based at the University of California, Los Angeles.
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Strong Magnitude 7.8 earthquake hits near Ecuador tsunami warning issued

Magnitude 7.8 earthquake hits Ecuador's coastal region

7.4 quake reported in Ecuador
A powerful 7.8 magnitude earthquake has hit Ecuador's central coast, felt as far away as the capital, where people fled shaking buildings.
The quake was reported at 4:58 p.m. Pacific time, 17 miles from Muisne, according to the U.S. Geological Survey. The depth was recorded at 12.4 miles.
The earthquake shook buildings in the capital, Quito, for about 40 seconds, and many people fled into the streets. Quito is about 107 miles from the quake's epicenter.
There were no immediate reports of major damage Saturday.
This information comes from the USGS Earthquake Notification Service and this post was created by an algorithm written by the author. The Associated Press contributed to this report.
This is a developing story. Check back for updates as more information becomes available.

Time

  1. 2016-04-16 23:58:37 (UTC)
  2. 2016-04-17 08:58:37 (UTC+09:00) in your timezone
  3. Times in other timezones

Nearby Places

  • 27.0 km (16.8 mi) SSE of Muisne, Ecuador
  • 52.0 km (32.3 mi) W of Rosa Zarate, Ecuador
  • 68.0 km (42.3 mi) SSW of Propicia, Ecuador
  • 111.0 km (69.0 mi) NW of Santo Domingo de los Colorados, Ecuador
  • 170.0 km (105.6 mi) WNW of Quito, Ecuador

Seismotectonics of South America (Nazca Plate Region)


The South American arc extends over 7,000 km, from the Chilean margin triple junction offshore of southern Chile to its intersection with the Panama fracture zone, offshore of the southern coast of Panama in Central America. It marks the plate boundary between the subducting Nazca plate and the South America plate, where the oceanic crust and lithosphere of the Nazca plate begin their descent into the mantle beneath South America. The convergence associated with this subduction process is responsible for the uplift of the Andes Mountains, and for the active volcanic chain present along much of this deformation front. Relative to a fixed South America plate, the Nazca plate moves slightly north of eastwards at a rate varying from approximately 80 mm/yr in the south to approximately 65 mm/yr in the north. Although the rate of subduction varies little along the entire arc, there are complex changes in the geologic processes along the subduction zone that dramatically influence volcanic activity, crustal deformation, earthquake generation and occurrence all along the western edge of South America. 
Most of the large earthquakes in South America are constrained to shallow depths of 0 to 70 km resulting from both crustal and interplate deformation. Crustal earthquakes result from deformation and mountain building in the overriding South America plate and generate earthquakes as deep as approximately 50 km. Interplate earthquakes occur due to slip along the dipping interface between the Nazca and the South American plates. Interplate earthquakes in this region are frequent and often large, and occur between the depths of approximately 10 and 60 km. Since 1900, numerous magnitude 8 or larger earthquakes have occurred on this subduction zone interface that were followed by devastating tsunamis, including the 1960 M9.5 earthquake in southern Chile, the largest instrumentally recorded earthquake in the world. Other notable shallow tsunami-generating earthquakes include the 1906 M8.5 earthquake near Esmeraldas, Ecuador, the 1922 M8.5 earthquake near Coquimbo, Chile, the 2001 M8.4 Arequipa, Peru earthquake, the 2007 M8.0 earthquake near Pisco, Peru, and the 2010 M8.8 Maule, Chile earthquake located just north of the 1960 event. 
Large intermediate-depth earthquakes (those occurring between depths of approximately 70 and 300 km) are relatively limited in size and spatial extent in South America, and occur within the Nazca plate as a result of internal deformation within the subducting plate. These earthquakes generally cluster beneath northern Chile and southwestern Bolivia, and to a lesser extent beneath northern Peru and southern Ecuador, with depths between 110 and 130 km. Most of these earthquakes occur adjacent to the bend in the coastline between Peru and Chile. The most recent large intermediate-depth earthquake in this region was the 2005 M7.8 Tarapaca, Chile earthquake. 
Earthquakes can also be generated to depths greater than 600 km as a result of continued internal deformation of the subducting Nazca plate. Deep-focus earthquakes in South America are not observed from a depth range of approximately 300 to 500 km. Instead, deep earthquakes in this region occur at depths of 500 to 650 km and are concentrated into two zones: one that runs beneath the Peru-Brazil border and another that extends from central Bolivia to central Argentina. These earthquakes generally do not exhibit large magnitudes. An exception to this was the 1994 Bolivian earthquake in northwestern Bolivia. This M8.2 earthquake occurred at a depth of 631 km, which was until recently the largest deep-focus earthquake instrumentally recorded (superseded in May 2013 by a M8.3 earthquake 610 km beneath the Sea of Okhotsk, Russia), and was felt widely throughout South and North America. 
Subduction of the Nazca plate is geometrically complex and impacts the geology and seismicity of the western edge of South America. The intermediate-depth regions of the subducting Nazca plate can be segmented into five sections based on their angle of subduction beneath the South America plate. Three segments are characterized by steeply dipping subduction; the other two by near-horizontal subduction. The Nazca plate beneath northern Ecuador, southern Peru to northern Chile, and southern Chile descend into the mantle at angles of 25° to 30°. In contrast, the slab beneath southern Ecuador to central Peru, and under central Chile, is subducting at a shallow angle of approximately 10° or less. In these regions of “flat-slab” subduction, the Nazca plate moves horizontally for several hundred kilometers before continuing its descent into the mantle, and is shadowed by an extended zone of crustal seismicity in the overlying South America plate. Although the South America plate exhibits a chain of active volcanism resulting from the subduction and partial melting of the Nazca oceanic lithosphere along most of the arc, these regions of inferred shallow subduction correlate with an absence of volcanic activity.
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Strong Earthquake Strikes Japan’s Kyushu Island, Killing at Least 3

A collapsed wall in Mashiki, Kumamoto Prefecture, after a strong earthquake struck Japan on Thursday. Kyodo News, via Reuters 

TOKYO — A powerful earthquake struck the southwestern Japanese island of Kyushu on Thursday, killing at least three people, damaging buildings and knocking out power, the Japanese news media reported.

Television images showed firefighters battling blazes in the most seriously affected area, in the town of Mashiki in rural Kumamoto Prefecture. The roofs of some homes appeared to be partly collapsed, with tiles spilling onto the narrow streets.

The local authorities in Kumamoto said they had received a number of reports of people trapped under collapsed buildings, according to NHK, the national broadcast network.

Hospitals in Kumamoto city, the prefecture’s capital, reported that three people had been killed, according to NHK. One hospital said it was treating 88 people for injuries, seven of them serious.

The earthquake knocked an out-of-service Shinkansen bullet train off its rails, JR Kyushu Railway reported. There were no passengers on the train at the time and no one was injured, the railway said.

Continue reading the main story

The Japan Meteorological Agency reported the quake’s preliminary magnitude at 6.4, strong but not at the top of the range for seismically unstable Japan. The earthquake that struck northeastern Japan in 2011, unleashing a powerful tsunami, measured 9.0.

But the quake on Thursday was centered on land, unlike the offshore quake five years ago, and its origin point was a relatively shallow six miles below the surface. As a result, there was no tsunami, but the shaking at the epicenter was especially strong.

In Mashiki, groups of people gathered in parking lots, parks and other open spaces after fleeing their homes, as powerful aftershocks continued to rattle the region. Officials warned residents not to approach damaged buildings for fear that they could collapse.

A measure of surface vibration used by the meteorological agency was reported at the top of a seven-step scale in Mashiki — the same as the 2011 quake. The quake struck at 9:26 p.m., and power failures left rescue workers searching in the dark for possible victims.

“We don’t yet know the extent of the damage, but we are putting all our efforts into gathering information,” said Yoshihide Suga, the government’s chief cabinet secretary.

Kyushu is home to the only Japanese nuclear power plant currently in operation, after a mass shutdown of the atomic-power industry following the 2011 quake, which caused meltdowns at a plant in Fukushima.

Kyushu Electric Power Company said there were no problems at the two reactors that are online at the facility, the Sendai Nuclear Power Plant, which is about 75 miles southwest of Mashiki.

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Magnitude 7.2 Vanuatu earthquake: Tsunami alert issued after powerful tremor near Port-Olry

 


PUBLISHED SUN, APRIL 03, 2016 - 4:42AM EDT

  Credit: USGS 


UPDATE: The tsunami alert has been stood down by the Pacific Tsunami Warning Center. More to come..

A powerful earthquake with a preliminary magnitude of 7.2 has struck the Pacific Ocean near the Vanuatu Islands, seismologists say. There was no immediate word on damage or casualties but a tsunami alert has been issued. (more) 





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The earthquake, which struck at 8:23 GMT on Sunday, was centered about 81 kilometers (50 miles) northwest of Port-Olry a town in Sanma province on the island of Espiritu Santo, or 407 kilometers (253 miles) northwest of the capital Port-Vila. It struck about 35 kilometers (21.7 miles deep).

The Pacific Tsunami Warning Center, which put the earthquake's preliminary magnitude at 7.2, said a tsunami is possible and issued a tsunami threat message for Vanuatu. "Hazardous tsunami waves from this earthquake are possible within 300 km of the epicenter along the coasts of Vanuatu," it said.

It was not immediately clear whether a tsunami warning was in effect because the Pacific Tsunami Warning Center no longer issues formal warnings, and there was no immediate word from the Vanuatu Tsunami Warning Center.

The United States Geological Survey (USGS) estimated that some 186,000 people in the region may have felt the earthquake, including an estimated 18,000 people who may have experienced "strong" to "very strong" shaking. There was no immediate word about damage or casualties.

Vanuatu is on the so-called 'Pacific Ring of Fire', an arc of fault lines circling the Pacific Basin that is prone to frequent and large earthquakes. On average, the island nation and the surrounding waters are struck by about three powerful earthquakes every year. Volcanic eruptions also occur frequently in the region.

In August 2011, two powerful earthquakes measuring 7.1 and 7.4 on the Richter scale struck about 63 kilometers (39 miles) south-southwest of Port-Vila. Tsunami waves of up to 1.05 meter (3.4 feet) were observed on the island of Efate, but there were no reports of damage.

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Solar phenomenon could confuse birds, GPS systems this weekend

Birds flying north for the spring and humans relying on global positioning satellites to navigate could get a little lost this weekend.

Three coronal holes spread across the sun are pointing at the Earth. As a result, a minor geomagnetic storm alert has been issued for Saturday by the U.S. Space Weather Prediction Center in Boulder, Colorado, and the Space Weather Operations Centre of the U.K. Met Office in Exeter.

“Early on Day 3 (2nd April), a high-speed stream from coronal hole 67 is expected to reach Earth,” said the Met Office.

Forecasters in the U.S. and Britain predict this could confuse migrating birds and other animals, cause minor problems with satellites and make an aurora visible as far south as Maine and Michigan.

The storms could rise to G2 level on a five-step scale, which would mean the Northern Lights might be seen in New York and some electrical transformers could be damaged.

Viewed through X-ray telescopes, coronal holes can appear to be vast, dark, blank spaces in sun’s swirling atmosphere. They are the places where the sun’s magnetic lines don’t return to the surface.

To see how that works, touch your fingertips together: They form an arc, which is what the magnetic lines do on the sun. Now spread your fingers outward so they aren’t touching and are pointing away from you. This is what happens with the magnetic lines on the sun when a coronal hole opens.

The solar wind, a stream of charged particles flowing away from the sun, bursts out with greater velocity from the coronal holes. When the holes point at the Earth, the planet is caught in even stronger winds and the chances of geomagnetic storms increase.

So if you run into a lost bird Saturday, help the little fellow on his way. That is, if you know where you are yourself.

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