Photographic Image by NASA/JPL-Caltech/Univ. of Arizona
During a recent calibration exercise, NASA’s Mars Reconnaissance Orbiter captured a remarkable view of Earth and its moon from a distance of 127 million miles (205 million kilometers).
It’s so clear, you can even make out our planet’s continents.
To calibrate the HiRISE camera aboard the Mars Orbiter, NASA scientists needed to scan an object other than the Red Planet.
Seeing as Earth is right next door, that was an obvious choice.
The image is a combination of two separate exposures taken on November 20, 2016, and have been moderately adjusted to make both objects appear equally as bright (otherwise the Earth would have appeared too dark).
The combined view shows the correct positions and sizes of the two celestial bodies relative to each other.
On February 18, 1930, Clyde W. Tombaugh, an assistant at the Lowell Observatory in Flagstaff, Arizona, discovered Pluto. For over seven decades, Pluto was considered the ninth planet of our solar system.
It was American astronomer Percival Lowell who first thought there might be another planet somewhere near Neptune and Uranus.
Lowell had noticed that the gravitational pull of something large was affecting the orbits of those two planets.
However, despite looking for what he called “Planet X” from 1905 until his death in 1916, Lowell never found it.
Thirteen years later, the Lowell Observatory decided to recommence Lowell’s search for Planet X.
They had a more powerful, 13-inch telescope built for this sole purpose. The Observatory then hired 23-year-old Clyde W. Tombaugh to use Lowell’s predictions and the new telescope to search the skies for a new planet.
It took a year of detailed, painstaking work, but Tombaugh did find Planet X.
The discovery occurred on February 18, 1930 while Tombaugh was carefully examining a set of photographic plates created by the telescope.
Despite Planet X being discovered on February 18, 1930, the Lowell Observatory was not quite ready to announce this huge discovery until more research could be done.
After a few weeks, it was confirmed that Tombaugh’s discovery was indeed a new planet.
On what would have been Percival Lowell’s 75th birthday, March 13, 1930, the Observatory publicly announced to the world that a new planet had been discovered.
Pluto was re-classified as a Dwarf Planet in 2006, thus losing its planetary status.
An artist’s rendering of the collision that created the moon (Paul Wootton/ /Science Photo Library/Corbis)
Scientists have announced that they had found evidence of the planetary body that slammed into the earth over four billion years ago, creating the moon.
In analyzing lunar rocks collected on the Apollo missions, they found that the moon rocks contained different ratios of oxygen isotopes 17 and 16 than their earthly counterparts, showing that some percentage of the moon likely had to come from somewhere else.
Daniel Herwartz, lead author of the study told Space.com:
“The differences are small and difficult to detect, but they are there,” Herwartz said. “We now get an idea of the composition of Theia.”
That was the name given to the Mars-sized planet in 2000 by Alex Halliday.
Most scientists 14 years ago had started to accept the giant impact hypothesis, first proposed in the 1970s, and when Halliday proposed calling the planet Theia, the name caught on.
But what people couldn’t figure out was where all the evidence for Theia had gone.
The earth and moon have very similar chemical compositions. So similar, if fact, that it’s been a huge puzzle for scientists trying to prove the Giant Impact Theory.
With this new research there is finally some difference. Or is there?
There is still considerable scientific research looking in to moon formation, along with a lot of debate, so it’s no surprise really that not everyone in the scientific community agrees that the differing oxygen isotopes are conclusive enough evidence for Theia.