Tag Archives: Earth

One Year on Earth – Seen From 1 Million Miles

An evening pause: This video release from NASA made the rounds a few weeks ago. It isn’t news, but it is cool. One important fact noted during this video is that the Earth’s cloud cover both warms and cools the planet. What wasn’t noted was that there is gigantic uncertainty about how much the clouds warm and cool, which is one of the main reasons no climate models have been even close to successfully predicting the climate.

Hat tip Wayne DeVette.

Earth’s magnetic field might not be flipping

The uncertainty of science: A new analysis of the past strength of the Earth’s magnetic field suggests that today’s field is abnormally strong and that, even with the 10% decline in the field’s strength in the past two centuries, it remains stronger than the average over the past 5 million years.

The new data also suggests that the field might not be about to shut down and then reverse polarity, as some scientists have theorized based on the 10% decline. Instead, the data says that the field’s unusual strength today only means that the decline is bringing it back to its average strength, and is not necessarily an indication of a pending reversal.

To put it mildly, there are a lot of uncertainties here, including questions about the database that has been used previously by geologists to estimate the past strength of the Earth’s magnetic field. The database might have been right, but the new study raises significant new questions.

The Earth from a million miles away

Earth from a million miles away

Cool image time! NASA’s DISCOVR solar observation probe has released its first image of the Earth, taken from its station-keeping position a million miles from Earth.

This camera was originally designed for Al Gore’s proposed propaganda mission where a spacecraft would take daily pictures of the Earth to pound home his environmental agenda. Eventually NASA found a real use for the satellite’s overall structure and location, observing the Sun’s activity and give us advance warning of dangerous flares or coronal mass ejections.

They left the Earth-viewing camera on board, partly because it was built already (it would cost money to remove) and partly because daily images like this can be of some scientific value.

An iron rain fell on Earth early in its formation

New research attempting to explain why the Earth but not the Moon has so much iron splattered through its mantle has found that iron can be more easily vaporized during impacts than previously thought, and thus rained down on the planet during the early asteroid bombardment.

Principal investigator Kraus said, “Because planetary scientists always thought it was difficult to vaporize iron, they never thought of vaporization as an important process during the formation of the Earth and its core. But with our experiments, we showed that it’s very easy to impact-vaporize iron.” He continued, “This changes the way we think of planet formation, in that instead of core formation occurring by iron sinking down to the growing Earth’s core in large blobs (technically called diapirs), that iron was vaporized, spread out in a plume over the surface of the Earth and rained out as small droplets. The small iron droplets mixed easily with the mantle, which changes our interpretation of the geochemical data we use to date the timing of Earth’s core formation.”

The Moon’s gravity in turn wasn’t sufficient to pull its own iron vapor down. Thus, it does not have much iron in its mantle.

The existence of a Kepler-found earth-sized planet in the habitable zone has been confirmed.

Worlds without end: The existence of a Kepler-found earth-sized planet in the habitable zone has been confirmed.

The newfound planet, called Kepler-186f, was first spotted by NASA’s Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth’s sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say.

In this new work, the Keck and Gemini ground-based telescopes confirmed Kepler’s discovery.

After the unmanned probe Juno zipped past the Earth on its way to Jupiter today, it unexpectedly went into safe mode.

After the unmanned probe Juno zipped past the Earth on its way to Jupiter today, it unexpectedly went into safe mode.

Engineers continued to diagnose the issue, which occurred after Juno whipped around Earth in a momentum-gathering flyby. Up until Wednesday, Juno had been in excellent health. While in safe mode, it can communicate with ground controllers, but its activities are limited.

It is unclear at the moment why this happened.

A special issue from Nature: Peopling the planet.

A special issue from Nature: Peopling the planet.

I haven’t yet had time to read this special issue, but it will certainly be fascinating, as it apparently summarizes the most current knowledge scientists have about the manner and timing of the human migration of the entire surface of the Earth. Overall, it appears that this migration took place sooner and faster than previously believed. Definitely worth a read.

The orbit of a 150 foot wide asteroid that zipped past the Earth in February, has an orbit so much like the Earth’s that astronomer’s expect it back next year.

Duck! The orbit of a 150 foot wide asteroid that zipped past the Earth in February, has an orbit that will bring it past the Earth again on February 15, 2013 by less than 15,000 miles.

The team use several automated telescopes to scan the sky, and the discovery came somewhat serendipitously after they decided to search areas of the sky where asteroids are not usually seen. “A preliminary orbit calculation shows that 2012 DA14 has a very Earth-like orbit with a period of 366.24 days, just one more day than our terrestrial year, and it ‘jumps’ inside and outside of the path of Earth two times per year,” says Jaime.

While an impact with Earth has been ruled out on the asteroid’s next visit, astronomers will use that close approach for more studies and calculate the Earth and Moon’s gravitational effects on it.

Because this newly discovered asteroid passes so close and frequently to both the Earth and Moon, astronomers will need a lot more data before they can pin down its orbit precisely, and thus predict the chances of a collision in the near future.

When a solar storm slammed into both the Earth and Mars in January 2008, scientists were able to directly measure the importance of the Earth’s magnetic field in protecting our atmosphere from oxygen loss.

When a solar storm slammed into both the Earth and Mars in January 2008, scientists were able to directly measure the importance of the Earth’s magnetic field in protecting our atmosphere from oxygen loss.

They found that while the pressure of the solar wind increased at each planet by similar amounts, the increase in the rate of loss of martian oxygen was ten times that of Earth’s increase. Such a difference would have a dramatic impact over billions of years, leading to large losses of the martian atmosphere, perhaps explaining or at least contributing to its current tenuous state. The result proves the efficacy of Earth’s magnetic field in deflecting the solar wind and protecting our atmosphere.

Juno looks back and sees the Earth and the Moon

Earth and Moon

Juno, on its way to Jupiter, took a look back and snapped this picture of the Earth/Moon double planet.

The image was taken by the spacecraft’s camera, JunoCam, on Aug. 26 when the spacecraft was about 6 million miles (9.66 million kilometers) away.

Gives us a glimpse at what our home planet will really look like to future spacefarers, either on they way out or on their way home.

Astronomers identify Earth’s first Trojan asteroid

Astronomers have spotted the first Trojan asteroid to the Earth.

The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth’s orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth. The asteroid’s orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).

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