Mariner 10 launched 1973

Mariner 10, launched November 3, 1973, was the first spacecraft to to visit two planets.  It was the last spacecraft of the Mariner program.  It made a flyby of Venus in February 1974.  It proceeded to make three flybys of Mercury in March 1974, September 1974 and then March 1975.  

Mariner 10 was decommissioned shortly after.

Mariner 10 second flyby of Mercury 1974

Mariner 10, launched in November 1973, made its second of three flybys of Mercury September 21, 1974. It had made a flyby of Venus prior to its first visit of Mercury.  Mariner 10 managed to photograph almost half of the planet during its second encounter.  It flew within 30,000 miles of the southern hemisphere.

Mariner 10 makes third, final, and closest flyby of Mercury 1975

Mariner 10 made its third and last flyby of the planet Mercury, March 16, 1975.  The probe was launched November 3, 1973, the last of NASA's Mariner program and made a flyby of Venus February 5, 1974. 

It made three flybys of Mercury, the last being the closest at 203 miles above the surface near the north pole.  Mariner 10 discovered a tenuous atmosphere consisting of helium, a magnetic field and a large, iron-rich core.  Daytime temperatures can reach 369 °F and nighttime temperatures can drop as low as -297 °F.

Mariner 10 remains in orbit around the sun.

The Donald's EPA caught illegally rescinding Mercury rule

One of The Donald's first acts after purchasing the White House in January was:

"to “immediately withdraw” final rules sent to the Office of the Federal Register but not yet published in the Federal Register."

Although not yet under Pruitt's despotism, the TEPA (Trump's EPA) rescinded the Mercury Effluent Rule, which had been finalized December 15, 2016.  The EPA is required to give public notice and an opportunity to comment, but did not.

The National Resources Defense Council acted quickly and sued the EPA for acting illegally and potentially putting millions at risk.  Mercury is a neurotoxin and dental offices are the main source of mercury discharges to municipal wastewater treatment plants, since excess amalgam from new cavitgy fillings or old amalgam fillings being replaced are flushed down the drain.   However, coal-fired power plants (quelle surprise!) industrial boilers, and cement plants and mining sites can discharge mercury into the environment.

Mercury is especially dangerous to pregnant women, babies and toddlers.  Even tiny amounts of exposure can disrupt brain function and harm the nervous system.  The Mercury Effluent Rule reduces the annual discharge of mercury by 5.1 tons to publicly owned WWTPs.  And dental offices are in support of this rule.  Mercury is hard to remove from wastewater streams so this is why it is so important to stem the discharge of the metal to the environment.

What part of this does The Donald and Pruitt not understand?

Fortunately, the NRDC was successful and June 9, the EPA restored the rule.


https://www.nrdc.org/experts/mae-wu/factsheet-limiting-mercury-pollution
 https://www.nrdc.org/media/2017/170609-1&s_src=FBNews&utm_source=fb&utm_medium=post&utm_campaign=mercury
https://www.nrdc.org/trump-watch/epa-restores-mercury-protection-rule-thanks-nrdc-lawsuit?utm_source=tw&utm_medium=tweet&utm_content=socialmedia
https://www.nrdc.org/trump-watch/epa-illegally-rolls-back-protections-mercury-pollution

Mercury Program Astronaut Scott Carpenter born 1925

Malcolm Scott Carpenter, born in Boulder, Colorado May 1, 1925, was one of seven original astronauts chosen for NASA's Project Mercury program in 1959.  He became the 4th American in space and the 2nd to orbit Earth, after John Glenn and the first to eat solid food in space.

This was his only flight as he received an injury from a motorcycle accident in 1963, which grounded him.  He was hospitalized in September 2013 after a stroke and passed away October 10, 2013 in Denver.

Mariner 10 flies by Mercury, 1974

Mariner 10, launched November 3, 1973, became the first spacecraft to encounter Mercury, the closest planet to the Sun. It made ultraviolet observations of Comet Kohoutek in January 1974 and passed Venus February 5. It made its first flyby of Mercury March 29, 1974.  The second was September 21 and the third (and last) March 16, 1975.

It was decommissioned about a week later.

Enos the Chimp launched in Mercury-Atlas 5, 1961

Although the Soviets had already put two cosmonauts (Yuri Gagarin being the first) into orbit by November 1961, NASA was still debating putting a man into orbit.  On November 29, 1961, Enos, a chimpanzee, was launched in the Mercury-Atlas 5 from Cape Canaveral.  He made two orbits of Earth and splashed down off the coast of Puerto Rico a little over three hours from lift-off.  Enos carried out a series of tests and came through unharmed.

The Mercury spacecraft was deemed ready for human occupants.

John Glenn returns to space 1998

Space Shuttle Discovery Crew - Back row: Mission Specialist 2 Scott E. Parazynski, Payload Specialist 1 Chiaki Mukai, Mission Specialist 1 Pedro Duque, Payload Specialist 2 John H. Glenn, Jr.

Front row: Pilot Steven W. Lindsey, Commander Curtis L. Brown, Jr.

Astronaut and senator John Glenn returned to space on board the Space Shuttle Discovery (STS-95), October 29, 1998.  He became the oldest man to date to go into space.  Also aboard was Pedro Duque of Spain, the country's first astronaut.  The rest of the crew consisted of Commander Curtis Brown, Pilot Steven Lindsey, Scott Parazynski, Stephen Robinson and Chiaki Mukai.

Glenn made history as part of NASA's Mercury project to become the first American to orbit Earth. in the Friendship 7 in 1962.  His second return to space was at the age of 77 as a payload specialist.  NASA conducted experiments on Glenn while in space to give them an understanding of the effects of space on aging.

We are (probably) not alone! First exoplanet discovered 1995

 

Artist's depiction of exoplanet 51 Pegasi b

October 6, 1995, European scientists Michel Mayor and Didier Queloz announced the discovery of a planet orbiting another star.  Planet 51 Pegasi b is about half the size of Jupiter and a "year" is just four Earth days.  And it orbits its sun 51 Pegasi at a distance of 0.05 AU (astronomical units) which is about 1/6 the distance between Mercury and our sun.  That means the surface temperature is around a sultry 2-3000 Kelvin.

In the 21 years since, over 1800 exoplanets have been discovered, including (perhaps) Tatooine, Vulcan and Krypton.

How to find Star 51 Pegasi

http://zebu.uoregon.edu/51peg.html

http://www.jpl.nasa.gov/news/news.php?feature=4674

http://www.jpl.nasa.gov/news/news.php?release=2015-312

MESSENGER, spacecraft to Mercury, launched 2004

Artist's rendering of MESSENGER in orbit around Mercury.

MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) launched August 3, 2004 was the first spacecraft to orbit the planet closest to the sun in our solar system. On March 18, 2011 it achieved orbit. It was planned to orbit Mercury for only a year but lasted over four. With seven scientific instruments on board, the craft sent back over 10TB of data, including almost 300,000 images and numerous map products.

In May 2016, NASA released a 3-D image of the first global topographic model of Mercury (see video below).  The extent of the data received from MESSENGER will keep scientists busy for years to come.

First photo from orbit.

On April 30, 2015, MESSENGER yielded to Mercury’s gravity and crashed on the surface just north of the Shakespeare basin. It created a crater estimated to be 52 feet in diameter.

The last photo taken before impact.