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hibernation simply refers to the seasonal bodily changes that occur in some animals—slower heart rates, decreased oxygen intake, and a reduced ability to regulate body temperature

during hibernation, a lemur’s breathing can slow to one inhalation every 20 minutes, and its heart rate drops from a normal 200 beats per minute to just 4 beats per minute

lemurs can hibernate, surviving three-quarters of a year without deep sleep,

The longest a human has ever been recorded going without sleep is allegedly 18 days, 21 hours, and 40 minutes

severely sleep-deprived humans have a tendency to fall asleep for seconds at a time, it’s hard to prove such claims without brain monitoring

rapid eye movement (REM) sleep—which is when we dream

non-REM sleep. Non-REM sleep is vital. When you fall into bed after pulling an all-nighter

deep, non-REM sleep that you want

when lemurs hibernate, scientists speculate that they experience only REM sleep. Though no one can prove whether lemurs actually dream

primates exhibit all the telltale signs of a full night’s REM sleep such as increased brain activity, rapid eye movements, and muscle paralysis

A 1989 study by sleep scientist

demonstrated the lethal consequences of sleep deprivation

When the researcher kept ten rats awake, depriving them of non-REM sleep, they developed skin lesions, lost weight, and experienced an erosion of their gastrointestinal tracts.

After 32 days, all of the rats were dead

If you completely deprive animals of [non-REM] sleep, then they die

yet the lemurs that hibernate appear to be able to go for months without sleep…and they’re not dying

Lemurs in captivity often don’t hibernate

Some of [the lemurs hibernated] 40 feet off the ground in the middle of the forest in coastal Madagascar

team visited the primates in their natural habitat—Madagascar

By placing the lemurs in special nesting boxes and attaching EEGs to their tiny foreheads while they hibernated, Krystal was able to record their vital signs

found that when it was warm outside, close to 72 degrees Fahrenheit (22 degrees Celsius), the primates would only hibernate in REM sleep.

As temperatures inside the body fall, several failsafe systems spring into action

Blood vessels near the skin squeeze tight to hold warmth in, the body starts to shiver and brown fat, a tissue that’s especially plentiful in newborns, starts to produce heat

colleagues bypassed the rats’ defenses against the cold with a compound that’s similar to adenosine, a molecule in the body that signals sleepiness

After about an hour in a room chilled to 15° Celsius, the rats grew lethargic

brain waves slowed, their blood pressure dropped and their heart grew sluggish, occasionally skipping beats

The rats’ core temperature dropped from about 38°  to about 30° C, or 80° Fahrenheit

measured even lower temperatures in further experiments — rats’ core body temperature reached 15° C or about 57° F.

The rats weren’t in a coma, nor were they asleep or truly hibernating

Hibernating animals’ metabolisms plummet and their temperatures sink much lower

an Arctic ground squirrel, for instance, cools to about —3° C when it hibernates

It’s a new state

don’t really know what it is

In the experiment, loud noises and tail pinches failed to arouse the rats.

They didn’t eat or drink. Occasionally, one would slither into a corner, but for the most part, the animals stayed still for up to 6 hours

In unpublished experiments, Tupone has kept the animals in the unresponsive state for 24 hours, he says.

Warming the room coaxed the rats out of their torpor

The recovery process takes about 12 hours, during which the animals ate and drank voraciously

After recovering, the animals were alert, moved around their cages normally and slept when tired

When people have heart attacks or strokes, clinicians can use ice packs or frigid water to chill people and prevent further tissue damage

those methods of cooling take time and can have dangerous side effects

They went to sleep to conserve energy since there is no sunlight to generate power with the solar arrays during the lunar night.

During the nocturnal hiatus they were kept alive by a radioisotopic heat source that kept their delicate computer and electronics subsystems warmed inside a box below the deck

It was maintained at a temperature of about minus 40 degrees Celsius to prevent debilitating damage

lunar night time environment when temperatures plunged to below minus 180 degrees Celsius, or minus 292 degrees Fahrenheit

Just prior to hibernating, the lander snapped the first image of the Earth taken from the Moon’s surface in some four decades

Yutu has already resumed roving

The Chang’e-3 lander should survive at least a year.

The cause of the pre-hibernation malfunction may perhaps be traced back to a buildup of abrasive lunar dust, but no one knows at this time.

“Yutu suffered a control circuit malfunction in its driving unit,” according to a newly published report on March 1 by the state owned Xinhua news agency.

prevented Yutu from entering the second dormancy as planned

A functioning control circuit is required to lower the rovers mast

They must be folded down into a warmed electronics box to shield them from the damaging effects of the Moon’s nightfall when temperatures plunge dramatically to below minus 180 Celsius, or minus 292 degrees Fahrenheit.

The panel driving unit also helps maneuver the panels into position to efficiently point to the sun to maximize the electrical output

Chinese space engineers engaged in troubleshooting to try and identify and rectify the technical problems in a race against time to find a solution before the start of Lunar Night 3.

The 140 kilogram rover was unable to move during Lunar Day 3 due to the mechanical glitches.

“Yutu only carried out fixed point observations during its third lunar day

it did complete some limited scientific observations. And fortunately the ground penetrating radar, panoramic and infrared imaging equipment all functioned normally.

Yutu and the companion Chang’e-3 lander have again gone into sleep mode during Lunar Night 3 on Feb. 22 and Feb 23 respectively, local Beijing time.

the issue with the control circuit malfunction in its driving unit remains unresolved and a still threatens the outlook for Yutu’s future exploration.

Yutu is now nearing its planned 3 month long life expectancy

Chinese national flag

After rolling all six wheels into the dirt, Yutu

drove to a location about nine meters north of the lander, according to CCTV commentators

then turned around so that the red Chinese flag emblazoned on the front side would be facing the lander’s high resolution color cameras for the eagerly awaited portraits of one another

Yutu is nearly the size of a golf cart. It measures about 1.5 m x 1 m on its sides and stands about 1.5 m (nearly 5 feet) tall

Yutu will depart the landing site

and begin its own lunar trek that’s expected to last at least 3 months. Remove this ad

equipped with eight science instruments including multiple cameras, spectrometers, an optical telescope, ground penetrating radar and other sensors to investigate the lunar surface and composition

The radar instrument installed at the bottom of the rover can penetrate 100 meters deep below the surface to study the Moon’s structure and composition in unprecedented detail, according to

senior advisor of China’s lunar probe project,

A UV camera will study the earth and its interaction with solar wind and a telescope will study celestial objects

will also investigate the moon’s natural resources for use by potential future Chinese astronauts

Most of the science instruments are working including at least three cameras and the ground penetrating radar

the extremely cold lunar night and temperature fluctuations of more than 300 degrees Celsius – a great engineering challenge.

The rover will hibernate during the two week long lunar night

A radioisotopic heater will provide heat to safeguard the rovers computer and electronics