Category Astronomy

WHAT ARE LATITUDE AND LONGITUDE?

Every place on Earth’s surface can be pinpointed by two figures: its latitude and its longitude. Lines of latitude (called ‘parallels’) form rings around Earth, parallel to the equator. A place’s latitude is given in degrees (°) north or south of the equator, which is considered latitude 0°. On the other hand, lines of longitude (called ‘meridians’) run round Earth from north to south, dividing the world up like the segments of an orange.

A place’s longitude is given as degrees west or east of the prime meridian, which is longitude 0°.

Latitude and longitude are angles that uniquely define points on a sphere. Together, the angles comprise a coordinate scheme that can locate or identify geographic positions on the surfaces of planets such as the earth.

Latitude is defined with respect to an equatorial reference plane. This plane passes through the center C of the sphere, and also contains the great circle representing the equator. The latitude of a point P on the surface is defined as the angle that a straight line, passing through both P and C, subtends with respect to the equatorial plane. If P is above the reference plane, the latitude is positive (or northerly); if P is below the reference plane, the latitude is negative (or southerly). Latitude angles can range up to +90 degrees (or 90 degrees north), and down to -90 degrees (or 90 degrees south). Latitudes of +90 and -90 degrees correspond to the north and south geographic poles on the earth, respectively.
Longitude is defined in terms of meridians, which are half-circles running from pole to pole. A reference meridian, called the prime meridian , is selected, and this forms the reference by which longitudes are defined. On the earth, the prime meridian passes through Greenwich, England; for this reason it is also called the Greenwich meridian. The longitude of a point P on the surface is defined as the angle that the plane containing the meridian passing through P subtends with respect to the plane containing the prime meridian. If P is to the east of the prime meridian, the longitude is positive; if P is to the west of the prime meridian, the longitude is negative. Longitude angles can range up to +180 degrees (180 degrees east), and down to -180 degrees (180 degrees west). The +180 and -180 degree longitude meridians coincide directly opposite the prime meridian.

Credit: WhatIs.com

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When did Surveyor 3 land on the Moon?

Launched on April 17, 1967, Surveyor 3 was the third engineering flight of the Surveyor series and the second in the series to achieve a soft landing on the moon. It was based on Surveyor 3’s surface sampling tests that it was concluded that the lunar surface could hold the weight of an Apollo lunar module

The Apollo 11 mission will remain in the collective consciousness of human beings forever. This is because it was the first time we humans managed to set foot on our natural satellite, the moon.

It is important to remember that this was made possible due to a number of missions that preceded this one. Among these was the Surveyor 3 spacecraft which proved beyond doubt that an Apollo lunar module could indeed safely land on the moon’s surface.

The third engineering flight of the Surveyor series, this spacecraft was the first to carry a surface-sampling instrument that could reach up to 1.5 m from the lander and dig up to 18 cm. Unlike its predecessors, Surveyor 3 began its mission from a parking orbit around Earth on April 17, 1967.

Bouncing to a stop

While it became the second in the series after Surveyor 1 to achieve a soft landing on the moon three days later on April 20, it was far from smooth. As highly reflective rocks confused the landers descent radar, the main engine did not cut off at the correct moment during the descent to the lunar surface.

This meant that Surveyor 3 bounced off the moon, not once but twice-first to a height of 10 m and then again to a height of 3 m. It was third time lucky for Surveyor 3 as it landed softly in the southeastern region of Oceanus  Procellarum.

With its worst behind it. Surveyor 3 set out to do what it was sent to do. Within an hour after landing, the spacecraft began transmitting the first of over 6,000 TV pictures of the surrounding areas.

Similar to wet sand

The most important phase of the mission included deployment of the surface sampler for digging trenches, manipulating lunar material, and making bearing tests. Based on commands from Earth, the probe was able to dig four trenches, performing four bearing tests and 13 impact tests.

The results from these experiments were the most important aspect of this mission. The scientists were able to conclude that lunar soil’s consistency was similar to that of wet sand and that it would be solid enough to bear an Apollo lunar module when it landed.

The start of May saw the first lunar nightfall following the arrival of Surveyor 3. The spacecraft’s solar panels stopped producing electricity and its last contact with Earth was on May 4. While Surveyor 1 could be reactivated twice after lunar nights, Surveyor 3 could not be reactivated when it was attempted 336 hours later during the next lunar dawn.

Tryst with Apollo 12

That, however, wasn’t the last of what we heard about Surveyor 3. Four months after the huge success of Apollo 11, NASA launched Apollo 12 in November 1969. The lunar module of Apollo 12 showcased pinpoint landing capacity as the precise lunar touchdown allowed the astronauts to land within walking distance of the Surveyor 3 spacecraft. During their second extra vehicular activity on November 19, astronauts Charles Conrad, Jr. and Alan L. Bean walked over to the inactive Surveyor 3 lander and recovered parts, including the camera system and the soil scoop.

Just like moon rocks, these were returned to Earth for studying, as they offered scientists a unique chance to analyse equipment that had been subjected to long-term exposure on the moon’s surface. The studies of the parts showed that while Surveyor 3 had changed colour due to lunar dust adhesion and exposure to the sun, the TV camera and other hardware showed no signs of failure.

While NASA placed some of the Surveyor 3 parts into storage along with moon rocks and soil samples, the remaining parts found home elsewhere. Even though NASA treats them as lunar samples and not artefacts, they are greatly valued when gifted or loaned out, both to museums and individuals.

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How an astronaut’s spacesuit is made?

One of the weirdest features in space travel is the spacesuit worn by astronauts, with its huge spherical helmet, the tunic, the bulky gloves and boots and all the various gadgets and fittings.

The space-suit is a highly perfected machine in itself. It consists of no fewer than fifteen layers of special materials to protect the body of the astronaut. The space suit must provide oxygen for the astronaut to breathe and protect the astronaut from the vacuum and heat or cold of space. It must also be flexible enough to allow the astronaut to move freely. For travel in space, the astronaut wears an MMU (manned maneuvering unit), which contains small gas-powered thrusters. 

The space-suit must also contain food and water supplies, fitting to dispose of bodily wastes and surface to deflect heat and radiation. The helmet visor requires protective tilters to prevent the astronaut from viewing the Sun directly and risking severe dazzling and retinal burns. The suit also has to be fireproofed to the maximum possible extent.

The space-suit took years and millions of dollars to develop.

 

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Which mission by NASA will land the first woman and next man on the Moon by 2024?

With the Artemis program, NASA will land the first woman and next man on the Moon by 2024, using innovative technologies to explore more of the lunar surface than ever before. We will collaborate with our commercial and international partners and establish sustainable exploration by the end of the decade. 

Following a successful hot fire test, the core stage will be shipped to the agency’s Kennedy Space Center in Florida for integration with the spacecraft. NASA will launch an SLS and an Orion together on two flight tests around the Moon to check performance, life support, and communication capabilities. The first mission – known as Artemis I – is on track for 2021 without astronauts, and Artemis II will fly with crew in 2023.

In the Phase 1 plan, NASA notes additional details about conducting a new test during the Artemis II mission – a proximity operations demonstration. Shortly after Orion separates from the interim cryogenic propulsion stage, astronauts will manually pilot Orion as they approach and back away from the stage. This demonstration will assess Orion’s handling qualities and related hardware and software to provide performance data and operational experience that cannot be readily gained on the ground in preparation for rendezvous, proximity operations, and docking, as well as undocking operations in lunar orbit beginning on Artemis III.

In 2024, Artemis III will be humanity’s return to the surface of the Moon – landing the first astronauts on the lunar South Pole. After launching on SLS, astronauts will travel about 240,000 miles to lunar orbit aboard Orion, at which point they will directly board one of the new commercial human landing systems, or dock to the Gateway to inspect it and gather supplies before boarding the landing system for their expedition to the surface.

Wearing modern spacesuits that allow for greater flexibility and movement than those of their Apollo predecessors, astronauts will collect samples and conduct a range of science experiments over the course of nearly seven days. Using the lander, they will return to lunar orbit before ultimately heading home to Earth aboard Orion.

Work is progressing rapidly on the Gateway. NASA will integrate the first two components to launch – the power and propulsion element and the habitation and logistics outpost – in 2023. This foundation for the Gateway will be able to operate autonomously, conducting remote science experiments when astronauts are not aboard. NASA has selected the first two science instrument suites to conduct space weather investigations in lunar orbit before crew visits.

 

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How many women have flown in space so far?

As of December 2019, of the 565 total space travelers, 65 have been women. There have been one each from France, Italy, South Korea, and the United Kingdom; two each from Canada, China, and Japan; four from the Soviet Union/Russia; and 50 from the United States. The time between the first male and first female astronauts varied widely by country. The first astronauts originally from Britain, South Korea, and Iran were women, while there was a two-year gap in Russia from the first man in space on Vostok 1 to the first woman in space on Vostok 6. The time between the first American man and first American woman in space was 22 years between Freedom 7 and STS-7, respectively. For China, this interval was almost eight and a half years between the Shenzhou 5 and Shenzhou 9 space missions, and for Italy, there was approximately twelve years between the STS-46 and Expedition 42 spaceflights.

A span of 19 years separated the first and second women in space. They were cosmonauts on the Vostok 6 and Soyuz T-7 missions. Though the Soviet Union sent the first two women into space, only four of the women in space have been Russian or Soviet citizens. However, British, French, Italian, dual-citizen Iranian-American and South Korean women have all flown as part of the Soviet and Russian space programs. Similarly, women from Canada, Japan, and America have all flown under the US space program. A span of one year separated the first and second American women in space, as well as the first and second Chinese women in space, taking place on consecutive missions, Shenzhou 9 and Shenzhou 10.

 

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In 2006, which astronaut with Indian ancestry established a world record for women with four spacewalks?

Indian-American astronaut Sunita Williams, who holds the record of the longest space flight (195 days) for a woman, arrived at her new home amid stars with an international cast of crew for another four-month stay.

In 1993 she became a naval test pilot, and she later became a test pilot instructor, flying more than 30 different aircraft and logging more than 2,770 flight hours. When selected for the astronaut program, she was stationed aboard the USS Saipan.

Williams completed an M.S. in engineering management from the Florida Institute of Technology in Melbourne in 1995, and she entered astronaut training in 1998. She traveled to Moscow, where she received training in robotics and other ISS operational technologies while working with the Russian Federal Space Agency (Roskosmos) and with crews preparing for expeditions to the ISS.

 

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