“The lunar phase or phase of the moon is the shape of the illuminated (sunlit) portion of the Moon as seen by an observer on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing positions of the Moon and Sun relative to the Earth. The Moon’s rotation is tidally locked by the Earth’s gravity, therefore the same lunar surface always faces Earth. This face is variously sunlit depending on the position of the Moon in its orbit. Therefore, the portion of this hemisphere that is visible to an observer on Earth can vary from about 100% (full moon) to 0% (new moon). The lunar terminator is the boundary between the illuminated and darkened hemispheres. Each of the four “intermediate” lunar phases is roughly seven days (~7.4 days) but this varies slightly due to the elliptical shape of the Moon’s orbit. Aside from some craters near the lunar poles such as Shoemaker, all parts of the Moon see around 14.77 days of sunlight, followed by 14.77 days of “night”.”
“The flight [Friendship 7] occurred on February 20, 1962 from Cape Canaveral, later renamed Kennedy Space Center. There were eleven delays during the countdown due to equipment malfunctions, improvements to equipment that was functioning properly, and weather. During Glenn’s first orbit, there was a scheduled 30 minute test to see if Glenn could fly the spacecraft manually. This test became significant once a failure of the automatic control system was detected at the end of the first orbit. This forced Glenn to operate in manual mode for the second and third orbits, as well as re-entry.
Later in the flight, telemetry indicated that the heat shield had become loose. If the telemetry was correct, Glenn’s spacecraft would likely have been destroyed during re-entry due to the intense heat. Flight controllers had Glenn modify his re-entry procedure by keeping his retrorocket pack on over the shield to help retain it during re-entry. Leaving the retrorocket pack on caused large chunks of flaming debris to fly past the window of the capsule during re-entry, although Glenn thought it could have also been the heat shield. He told an interviewer, “Fortunately it was the rocket pack – or I wouldn’t be answering these questions.” After the flight, it was determined that the indicator was faulty.
Friendship 7 made splashdown 800 miles southeast of Cape Canaveral safely after his 4-hour, 55 minute flight. Glenn carried a note with him on the flight that read, “I am a stranger. I come in peace. Take me to your leader and there will be a massive reward for you in eternity,” translated into several different languages, in case he landed near islands in the South Pacific Seas. The original procedure called for Glenn to exit through the top hatch, but he was uncomfortably warm and decided that an egress through the side hatch would be faster. During the flight, he endured 7.8 G’s of acceleration and traveled a total of 75,679 statute miles at about 17,500 mph.
Glenn is honored by President Kennedy at temporary Manned Spacecraft Center facilities at Cape Canaveral, Florida, three days after his flight. The flight made Glenn the first American to orbit the Earth. This feat made Glenn the third American in space and the fifth human being in space. For Glenn the day became the “best day of his life,” while it also renewed America’s confidence. His voyage took place while America and the Soviet Union were in the midst of the Cold War and competing in the “Space Race.”
As the first American in orbit, Glenn became a national hero, met President Kennedy, and received a ticker-tape parade in New York City, reminiscent of that given for Charles Lindbergh and other great dignitaries. However, he became “so valuable to the nation as an iconic figure,” said NASA administrator Charles Bolden, that Kennedy would not “risk putting him back in space again.” Glenn’s fame and political attributes were noted by the Kennedys, and he became a personal friend of the Kennedy family. On February 23, 1962, President Kennedy awarded Glenn with the NASA Distinguished Service Medal.”
“The early life and professional career of American astronaut John Glenn. Several of the people who knew him “back when” in New Concord, Ohio take up a certain amount of time reminiscing on Glenn’s boyhood and then segues into the astronaut’s preparations for his space flight — three orbits around the earth, and then home again. Included are interior shots aboard the Friendship Seven space capsule, and Glenn’s comments as he works inside the capsule during this mission.”
“As it orbits Sol, (469219) 2016 HO3 appears to circle around Earth as well. The object is beyond the Hill sphere of Earth, meaning that the Sun exerts a stronger pull on it than Earth does. Although it is too distant to be considered a true natural satellite of Earth, it is the best and most stable example to date of a near-Earth companion, or quasi-satellite.
“Since 2016 HO3 loops around our planet, but never ventures very far away as we both go around the sun, we refer to it as a quasi-satellite of Earth,” said Paul Chodas, manager of NASA’s Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California.
“One other asteroid — 2003 YN107 — followed a similar orbital pattern for a while over 10 years ago, but it has since departed our vicinity. This new asteroid is much more locked onto us. Our calculations indicate 2016 HO3 has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern as Earth’s companion for centuries to come.”
In its yearly trek around the sun, asteroid 2016 HO3 spends about half of the time closer to the sun than Earth is (that is, the asteroid is inside the Earth’s orbit) and passes ahead of our planet, and about half of the time farther away (crosses outside Earth’s orbit), causing it to fall behind. Its orbit is also tilted a little, causing it to bob up and then down once each year through Earth’s orbital plane. In effect, this small asteroid is caught in a game of leap frog with Earth that will last for hundreds of years.
The asteroid’s orbit also undergoes a slow, back-and-forth twist over multiple decades. “The asteroid’s loops around Earth drift a little ahead or behind from year to year, but when they drift too far forward or backward, Earth’s gravity is just strong enough to reverse the drift and hold onto the asteroid so that it never wanders farther away than about 100 times the distance of the moon,” said Chodas. “The same effect also prevents the asteroid from approaching much closer than about 38 times the distance of the moon. In effect, this small asteroid is caught in a little dance with Earth.”
Asteroid 2016 HO3 was first spotted on April 27, 2016, by the Pan-STARRS 1 asteroid survey telescope on HaleakalÄ, Hawaii, operated by the University of Hawaii’s Institute for Astronomy and funded by NASA’s Planetary Defense Coordination Office. The size of this object has not yet been firmly established, but it is likely about 40–100 m (130–330 ft).”
“Launched ten years ago, on Oct. 25, 2006, the twin spacecraft of NASA’s STEREO mission – short for Solar and Terrestrial Relations Observatory – have given us unprecedented views of the sun, including the first-ever simultaneous view of the entire star at once. This kind of comprehensive data is key to understanding how the sun erupts with things like coronal mass ejections and energetic particles, as well as how those events move through space, sometimes impacting Earth and other worlds. Ten years ago, the twin STEREO spacecraft joined a fleet of NASA spacecraft monitoring the sun and its influence on Earth and space – and they provided a new and unique perspective.
The two STEREO observatories, called STEREO-A and STEREO-B – for Ahead and Behind, respectively – were sent out from Earth in opposite directions. Using gravitational assists from both the moon and Earth, the STEREO spacecraft were accelerated to Earth-escape velocities. STEREO-A was inserted into an orbit slightly smaller, and therefore faster, than Earth’s. For STEREO-B, the reverse happened: It was nudged into an orbit slightly larger than Earth’s so that it traveled around the sun more slowly, falling increasingly behind the Earth. As the spacecraft slowly fanned out away from the centerline between Earth and the sun – where every other sun-watching spacecraft is located – they revealed more and more new information about our closest star.”
Video credit: NASA’s Goddard Space Flight Center/Genna Duberstein/Scott Wiessinger
“On Sept. 8, NASA launched the Origins Spectral Interpretation Resource Identification Security – Regolith Explorer, or OSIRIS-REx mission from Cape Canaveral Air Force Station in Florida. OSIRIS-REx is the first U.S. mission to sample an asteroid. The spacecraft is scheduled to arrive at near-Earth asteroid Bennu in 2018, survey the asteroid’s surface, retrieve at least 60 grams (2.1 ounces) of surface material, and return the sample to Earth in 2023 for study. Analysis of the sample will reveal the earliest stages of the solar system’s evolution and the history of Bennu over the past 4.5 billion years.”
Subscribe to blog posts using RSS
