- hace 21 horas
Categoría
📺
TVTranscripción
00:00Número de nuestros planetes de solos son visitados por pruebas científicos más frecuentemente que otros.
00:16El diálogo de gas, Uranus y Neptuno, son tan distante que es difícil de alcanzar.
00:22Uranus es 20 veces más de la luz que la Earth, mientras que Neptuno es 30 veces más de la luz.
00:30Estas son las de las velocidades de NASA más de la luz que el planeta se ha visto en la luz que el planeta se ha visto en su dirección.
00:41La luz de la luz que el planeta se ha visto en su dirección, debe tomar un camino cercuo a través de la luz que el planeta se ha visto en la luz.
00:50La aeronol de Mariner 10 se voló a través de la luz de la luz en 1973 y la MESENGER Probe se voló a través de la luz de la luz de la luz en 2011.
01:00Venus presenta diferentes problemas.
01:08Aunque es nuestro vecino planetario y es más fácil para alcanzar,
01:13la lluvia de la lluvia ocupa sus features y su superficie tiene condiciones hellas.
01:18La lluvia de la lluvia rusa se ha lanzado,
01:27pero en el ambiente hostil no podrían sobrevivir solo por minutos.
01:48La plana de Venus
02:18de la luz, permitía calcular la distancia a la luz, que, en turn,
02:23podría unlockar más más acúrate metodos de navegación.
02:31En 1961, la Unión Soviética lanzó Venera I, la primera prueba de Venus.
02:40Se pasó Venus, pero la control de la misión ha perdido contacto.
02:48La siguiente año, la NASA lanzó Mariner I a Venus.
03:01A código error led a problemas de control con el lanzamiento.
03:08Fue destruido minutos después de la lanzamiento.
03:10Mariner II fue un aeropuerto.
03:14Porque conveniente oportunidades de lanzamiento solo ocurre en 18-month cycles,
03:18NASA tenía una segunda prueba preparada para lanzar.
03:21Mariner II was essentially a range of spacecraft designed to go to the moon.
03:28These were the early days of the space race,
03:30and the United States was desperate to catch up with the Soviet Union.
03:35Lead times were short,
03:36and the Jet Propulsion Laboratory did not have time to complete its original design.
03:48In August 1962, Mariner II was launched.
03:51The Ranger spacecraft launched toward the moon had all failed.
03:57Mariner II, on its way to Venus, was functioning,
04:02but its transmissions were weak,
04:04and due to a launch anomaly, it was off course.
04:06After a week, instructions for a complex course correction were transmitted to the spacecraft.
04:17About an hour later, Mariner executed the manoeuvre which involved a roll turn,
04:23followed by a pitch turn,
04:25and finally a main engine burn.
04:27It worked well, but several days later, the craft lost lock on the sun and the earth,
04:41its two attitude reference points.
04:44It corrected itself before ground control could diagnose the problem.
04:48Next, the signal strength increased to its normal level,
04:52but a short in a solar panel left it low on power.
04:57At this time, although both America and the Soviet Union
05:00had been sending probes toward the planets, nothing had succeeded.
05:05Mariner II lost several telemetry sensors, and it began to overheat.
05:10It continued limping toward Venus,
05:14but some of the spacecraft's problems were solving themselves.
05:18Mariner II was now close enough to the sun
05:21that it could function effectively on just one solar panel.
05:24It passed slightly less than 35,000 kilometres above Venus's cloud tops.
05:31It could detect no planetary magnetic field,
05:35and it recorded temperatures across the planet approaching 500 degrees Kelvin.
05:39Clearly, landing on the surface would present problems.
05:49But America wanted to focus on their first real success in space,
05:54finally doing something that the Soviets had not.
05:56Mariner II was the first successful interplanetary probe,
06:00and in California, the home of JPL, they celebrated.
06:02The next major advances in the exploration of Venus
06:04were made by the Soviet Union.
06:05The objective of the Venera series was to land on the surface of Venus.
06:11Designers understood that not only were the surface temperatures hot enough to melt lead,
06:15but that the atmospheric pressure was many times that of Earth.
06:19The landers they built looked more like diving bells than spacecraft.
06:21In June 1967, Venera IV was launched.
06:22In June 1967, the Venera IV was launched.
06:24The Venera series was to land on the surface of Venus.
06:25Designers understood that not only were the surface temperatures hot enough to melt lead,
06:30but that the atmospheric pressure was many times that of Earth.
06:34The landers they built looked more like diving bells than spacecraft.
06:47In June 1967, Venera IV was launched.
06:52The vehicle consisted of a carrier craft with instruments used during the cruise phase to Venus,
06:58and a spherical landing module that could communicate independently.
07:04After entry into the atmosphere, Venera IV's parachute opened.
07:09It sent back data for 93 minutes, but stopped 28 kilometers above the surface.
07:17Yet its electronics hadn't been overwhelmed by the heat.
07:20It had simply run out of power.
07:24Extrapolations from its final measurements showed a surface temperature of 500 degrees Celsius,
07:29and a pressure of 75 atmospheres, far higher than anyone expected.
07:36The Venera program strengthened its landers and fitted smaller parachutes to reduce descent time.
07:43Launched in January 1969, Venera V and VI learned more about the chemical makeup of the atmosphere,
07:49but neither remained functioning at the surface.
07:53The Venera series continued, refining the technology and making incremental improvements to mission duration,
07:58adding to the knowledge about Venus.
07:59In 1975, Venera V and VI was launched.
08:09In 1975, Venera IX was launched.
08:11It was a new design, consisting of an orbiter-lander combination,
08:20with the orbiter able to act as a relay station for signals transmitted from the surface.
08:25Four months after launch, the orbiter and the lander, encased in a spherical shell, separated.
08:39It entered the atmosphere two days later,
08:42while the mother craft became the first probe to go into orbit around Venus,
08:46photographing parts of the surface in ultraviolet.
08:49The new lander had a ring shield that could replace a parachute during the latter stages of the descent through the dense atmosphere.
09:02Venera IX transmitted the first black and white pictures from the surface,
09:06though a design fault meant a second camera could not eject its lens cap.
09:10Three days later, and 2,000 kilometers away, a twin craft, Venera X, landed.
09:20It took pictures too, but the same design fault left a lens cap stuck in place.
09:27Both landers had been pre-cooled while still in space,
09:31and circulating cooling fluid kept the craft operating on the blistering surface for more than an hour.
09:36In 1983, two more Venera craft arrived at Venus.
09:45Equipped with synthetic aperture radar,
09:48they made the first serious attempt to map the surface beneath the cloud layer.
09:55Over eight months, they mapped from the North Pole down to 30 degrees north.
09:59T-minus ten, nine, eight, seven, six.
10:10NASA had taken a minor role in the early exploration of Venus.
10:18But in 1989, the space shuttle Atlantis lifted off carrying the Magellan probe.
10:23Magellan was bound for Venus.
10:31Like the Venera craft before it, Magellan would use radar to map the surface of the planet.
10:38It was the first interplanetary spacecraft launched from the space shuttle.
10:44Following a cruise of 15 months, Magellan arrived at Venus and entered an elliptical orbit.
10:50To keep costs down, the probe had been built from an agglomeration of spare parts left over from previous NASA missions.
11:01After some software problems, it began mapping.
11:05The images it relayed remained the highest resolution pictures we have of the surface of Venus.
11:11Pictures of low volcanic blisters emerged, and lava channels were evidence of an extremely active surface.
11:21The thick atmosphere has prevented all but the largest meteors reaching Venusian ground,
11:27and few impact craters were visible.
11:30Yet evidence of plate tectonics that sculpts the Earth's surface was not obvious.
11:34After mapping Venus, Magellan changed its orbit and plotted the planet's gravitational anomalies.
11:45On Venus, localized changes in gravity correspond to surface features.
11:50On Earth, this is not the case.
11:52This is not the case.
11:55A new, naked picture of Venus emerged.
11:58The surface appears to have been completely remade around half a billion years ago.
12:03Yet while volcanoes and lava channels are common features on Venus,
12:08Magellan could not find evidence that volcanic activity still happens on the planet.
12:12In 2006, the European Space Agency's Venus Express went into orbit around Venus.
12:23Its focus was the long-term analysis of the planet's atmosphere.
12:29During its eight-year mission, it registered a sharp rise in the atmosphere's sulfur dioxide.
12:36This could be due to changes in wind patterns,
12:38but it could also be a sign of volcanic activity.
12:44Researchers also saw increases in infrared radiation coming from three different volcanic locations.
12:51More circumstantial evidence of current volcanic activity.
12:57Finally, the infrared team saw short-term temperature changes that fluctuated over just a few days.
13:02It appears that volcanoes may still be active on Venus.
13:11The mission ended in 2015, with a series of swoops into the upper atmosphere
13:17that verified unexpected ripples in the mesosphere.
13:24Very little in the way of Venus exploration has happened since Venus Express.
13:28Though elaborate plans exist for future missions to Venus, nothing at this stage has been funded.
13:35Yet many missions still pass close to Venus to use its gravitation to alter their flight paths.
13:43In 1974, Mariner 10 was the first spacecraft ever to use the gravitational slingshot effect on its way to Mercury.
13:53Italian mathematician Giuseppe Colombo devised the manoeuvre as a way to save fuel and to fly past Mercury not once but several times.
14:07The technique is now commonplace.
14:08Ten days after launch, Mariner 10 executed instructions for a routine course correction.
14:12This appeared to go well.
14:26But after the burn, when the craft attempted to reorient itself, there was a problem.
14:30Mariner 10 knew where it was pointing because its tracking sensor could lock onto the star Canopus.
14:39But a flake of paint that had come from the spacecraft was confusing the system.
14:44An automated backup procedure found Canopus again, but flaking paint was an issue for the rest of the mission.
14:50To reach Mercury, a spacecraft must approach the Sun, and its immense gravity presents a problem.
15:03Voyages to outer planets are constantly slowed by solar gravity.
15:07But with the inner planets, a spacecraft constantly accelerates.
15:11Mariner 10 used Venus's gravity to reduce its speed, and it approached Mercury at an acute angle.
15:21Mariner 10 did not have enough fuel to go into orbit around Mercury, but its Sun-centered path allowed the probe to make three close passes.
15:30Its first pass revealed a moon-like planet with a heavily cratered surface.
15:40Though Mercury is the smallest planet, it's the most dense.
15:45It has a large, iron-rich core.
15:49Prominent escarpments were seen.
15:52Here, Discovery Scarp cuts through two craters.
15:56It falls three kilometers.
15:57It's thought that these cliffs are the result of cooling and shrinking of the core.
16:03Mariner 10 continued to suffer technical problems.
16:07Its tape recorder kept sticking.
16:10There were restrictions in the rates of data transmission.
16:13And limited attitude control meant flight engineers were using solar pressure on the high-gain antenna and solar panels to compensate.
16:22Yet the mission continued.
16:23Mariner 10 could only map about 45% of Mercury's surface, as the same hemisphere faced the Sun during each of its passes.
16:33Mariner 10 discovered a very thin atmosphere, primarily of helium.
16:39Several months after its third and final pass of Mercury, it ran out of fuel.
16:43It still orbits the Sun.
16:46Main engine start.
16:47Two, one, and...
16:49It was more than 30 years before the next mission to Mercury.
16:55In 2004, Messenger was launched.
16:58It was designed to go into orbit around Mercury, which presented a number of design constraints.
17:08It featured a large woven ceramic sunshield, but it did not have a dish antenna.
17:15It would rely on a phased array that could be electronically pointed.
17:18After a year in space, Messenger was back at Earth, using its gravitation to modify its orbit.
17:28Even though it was not a large spacecraft, it had a powerful engine for course corrections and orbit insertion.
17:34It continued on to pass Venus twice to lose speed as it drew closer to the Sun.
17:44Three and a half years after launch, Messenger approached Mercury, but this was not the end of its journey.
17:52The probe made two more passes of Mercury, before finally going into orbit after almost seven years in space.
17:59Mission engineers had the extra problem of always requiring the probe's sunshield to be pointed toward the Sun.
18:11Because it was in orbit, Messenger was able to complete the mapping started by Mariner 10.
18:20The planet's dominant feature is the Caloris Basin.
18:23It's an ancient crater more than 1,500 kilometers across.
18:29Mariner 10 saw some of the area, but the rest had been in darkness.
18:36This map of the southern polar region uses color to represent illumination.
18:41Because Mercury's axis is not tilted, sunlight cannot penetrate deep craters near the poles.
18:47It was in these areas that Messenger discovered substantial amounts of water ice.
18:57Messenger received several mission extensions, but in 2015 it crashed into Mercury after running out of fuel.
19:07A new mission is already on its way to Mercury, Depi-Colombo, named after the designer of Mariner 10's trajectory.
19:14It's a joint effort between JAXA, the Japanese Space Agency, and the European Space Agency.
19:21It will take seven years to reach Mercury.
19:27The Voyager 2 spacecraft is the only probe to have made close approaches to the two outer ice giants, Uranus and Neptune.
19:37Launched in 1977 with its twin, Voyager 1, it was able to take advantage of a rare alignment of the four outer planets, enabling it to make close observations of each one.
19:54In 1986, Voyager approached Uranus.
19:56In the distant past, it must have been hit by another massive body that knocked its axis sideways.
20:06Uranus has an east and a west pole.
20:09And for half its orbit, one side sees continual sun, while the other remains in darkness.
20:15It has rings which follow its north-south equator.
20:18Voyager 2 discovered 11 new moons and a misaligned magnetic field.
20:27Images that the Voyager captured showed Uranus as a bland, featureless planet.
20:33But this was because of its particular season.
20:35With images from the Hubble Space Telescope, we now know that at certain times clouds and planetary weather appear in the atmosphere.
20:48Uranus's largest moon, Miranda, was observed in detail for the first time.
20:54So chaotic is its surface that researchers thought that it must have been blown apart by some cosmic impact, with the fragments reforming.
21:02Now it's thought that tectonic forces, initiated by the gravitation of Uranus, are responsible for the moon's jumbled appearance.
21:16As Voyager 2 left Uranus, backlighting from the Sun revealed two new rings encircling the planet.
21:22The spacecraft was now heading toward Neptune, the solar system's last planet.
21:33In the three years it would take to get there, ground engineers began preparing for unique challenges.
21:40Neptune is 30 times further from the Sun than the Earth, and the light intensity is 1,000th what it is here.
21:51For photography, time exposures would be necessary.
21:57Yet Voyager 2 was travelling so fast that images would smear without special preparation.
22:02Engineers calculated just how much the craft would have to swivel while exposures were made, to compensate for the probe's movement.
22:15In June 1989, Voyager 2 began returning distant images of Neptune.
22:26Across the world, people had realised that the data sent back to Earth by this spacecraft was transforming our understanding of the solar system.
22:34This was before the Internet age. Researchers at the Jet Propulsion Laboratory clustered around TV sets to watch as data and images came in line by line.
22:56Neptune is a more conventional planet than Uranus. Its axial tilt is 30 degrees, and it revolves in the same direction as the Earth.
23:04While Neptune is slightly heavier than its fellow ice giant Uranus, it has a slightly smaller diameter.
23:14And, though it is further from the Sun than its neighbour, Neptune emits more heat than Uranus.
23:21The planet has an internal heat source that drives more dynamic weather patterns.
23:25Voyager 2 measured wind speeds at Neptune in excess of 2,000 km per hour, the fastest in the solar system.
23:38There were cirrus clouds in the atmosphere, and the probe recorded pictures of a great dark spot, similar to Jupiter's great red spot.
23:45It was an anticyclone in the southern hemisphere, as large as the Earth.
23:54In 1994, when Hubble tried to find the same feature, it had disappeared, but a new dark spot was forming in the northern hemisphere.
24:02Voyager 2's last observations within the solar system were of Neptune's largest moon, Triton.
24:12Unlike all other moons in the solar system, Triton has a retrograde orbit, indicating that it was not formed at the same time as the planet, but that it had been captured.
24:22As Voyager 2 moved beyond the planets, its cameras would switch off to save power.
24:33Both Voyagers continue away from the solar system, measuring the influence of the solar wind.
24:41This remains the only mission to the ice giants.
24:44On January 19, 2006, an Atlas V was launched.
24:57It was a very powerful rocket with an unusually small payload.
25:04New Horizons left Earth orbit faster than any other probe.
25:07It was headed for the Kuiper belt at the outer edge of the solar system, in particular Pluto.
25:18In a little more than a year, New Horizons reached Jupiter, where it received a gravitational assist that cut three years from its flight time to Pluto.
25:27After it passed Jupiter, the spacecraft went into hibernation, simply sending an all's well transmission once a week.
25:40It took New Horizons more than nine years to reach Pluto.
25:45Since it had departed, Pluto had lost its status as a planet.
25:49With the discovery of more objects of similar size in the Kuiper belt,
25:53it was decided that to be a planet, a body had to clear its orbit.
26:02Pluto's features surprised everyone.
26:05Here was a living planet, shaped by tectonic forces,
26:09but instead of rock, the mountains were made of ice and frozen methane.
26:13And Pluto has a thin atmosphere, mainly of nitrogen.
26:16The probe continued on over Charon, Pluto's largest moon.
26:25Its icy surface has deep canyons, and some evidence suggests that it has ice volcanoes.
26:34Charon is about half the size of Pluto, and the two orbit each other.
26:40From Pluto, Charon would appear motionless in the sky.
26:45As the New Horizons probe sped away from Pluto into deep space,
26:50it began the slow process of transmitting its recorded data back to the Earth.
26:55At these distances, it takes signals four and a half hours to reach Earth,
27:00with data coming in at one kilobit per second.
27:08It took 469 days for all the Pluto information to be received back on Earth.
27:17Early in 2019, New Horizons passed trans-Neptunian object Ultima Thule,
27:22and, with a mission extension, it continues exploring the outer reaches of the solar system.
27:52To be continued...
27:54To be continued...
Comentarios