This will involve repeat passes just a few thousand kilometres above the cloudtops

La sonda espacial Juno ingresa en la órbita de Júpiter (Español/English+Video+Fotos)

Los ingenieros de la Nasa celebrando el exitoso arribo de la sonda Juno
Los ingenieros de la Nasa celebrando el exitoso arribo de la sonda Juno

Llegó a lo desconocido. Después de viajar cuatro años y once meses por el sistema solar, la sonda espacial Juno ingresó en la órbita de Júpiter este martes.

La nave de la Agencia Espacial de EE.UU. (NASA, por sus siglas en inglés) completó con éxito una riesgosa maniobra de 35 minutos: frenar los motores hacia abajo, de manera que pudiera ser aspirada en la órbita del planeta más grande del sistema solar.

En la sede de la NASA en Pasadena, California, los ingenieros gritaban de júbilo y se abrazaban tras confirmarse el éxito de la misión.    “Juno, bienvenido a Júpiter”, dijo uno de ellos.

“Qué gran día para celebrar (4 de julio, día de la independencia de Estados Unidos)”, dijo Jim Green, director de la División de Ciencias Planetarias de la Nasa. “Es un momento espectacular para nosotros”.

“Estoy muy emocionado, todo el equipo está emocionado. Ha sido un viaje increíble”, agregó emocionado Scott Bolton, investigador principal de la misión Juno.

“Finalmente estamos ahí. Júpiter es el rey de nuestro sistema solar, el más grande. Tenemos que ver qué hay dentro, cómo está formado, conocer sus verdaderos secretos”, comentó.

El más mínimo error podía acabar con un proyecto que ha costado US$1.100 millones.

Pero no hubo ningún incidente y ahora la nave Juno, construida como un tanque blindado, está en posición para orbitar durante un año Júpiter.

La sonda es patrocinada por la empresa Apple y tiene 4 años de viaje en el espacio
La sonda es patrocinada por la empresa Apple y tiene 4 años de viaje en el espacio

El objetivo de lamisión es entender cómo se formó este planeta, que según los científicos guarda los secretos de cómo se forman elementos como el agua, helio, metano e hidrógeno.

La información es esencial para saber cómo se formó nuestro sistema solar, la Tierra y los cimientos de la vida como la conocemos.

“Un Monstruo”

Júpiter es conocido como una implacable bola de gas.

Ha sido descrita por expertos de la NASA como “un monstruo que gira a tal velocidad que hace que su gravedad lance rocas gigantes, cometas, rayos cósmicos… hacia afuera”.

Esta es la razón por la que, según comentarios de astrónomos recogidos en el sitio de la NASA, lo que más temen los especialistas sobre esta misión es lo desconocido.

Además, durante el tiempo que dure la misión, Juno será expuesto al equivalente de más de 100 millones de radiografías de dientes.

“Las imágenes muestran la radiación extrema que rodea a Júpiter, que es un riesgo muy serio”, dijo Scott Bolton, investigador principal de la misión Juno.

Por eso la estrategia de esta misión es acercarse, tomar los datos y salir.

Juno ya se convirtió en la nave que más cerca ha estado del planeta gigante.   (BBC MUndo)

Juno probe enters into orbit around Jupiter

English

Juno probe enters into orbit around Jupiter

The US space agency has successfully put a new probe in orbit around Jupiter.

The Juno satellite, which left Earth five years ago, had to fire a rocket engine to slow its approach to the planet and get caught by its gravity.

A sequence of tones transmitted from the spacecraft confirmed the braking manoeuvre had gone as planned.

Receipt of the radio messages prompted wild cheering at Nasa’s Jet Propulsion Laboratory in Pasadena, California.

This will involve repeat passes just a few thousand kilometres above the cloudtops
This will involve repeat passes just a few thousand kilometres above the cloudtops

“All stations on Juno co-ord, we have the tone for burn cut-off on Delta B,” Juno Mission Control had announced. “Roger Juno, welcome to Jupiter.”

Scientists plan to use the spacecraft to sense the planet’s deep interior. They think the structure and the chemistry of its insides hold clues to how this giant world formed some four-and-a-half-billion years ago.

Engineers had warned in advance that the engine firing was fraught with danger.

No previous spacecraft has dared pass so close to Jupiter; its intense radiation belts can destroy unprotected electronics.

One calculation even suggested the orbit insertion would have subjected Juno to a dose equivalent to a million dental X-rays.

But the probe is built like a tank with titanium shielding, and the 35-minute rocket burn appeared to go off without a hitch.

“Nasa did it again,” said an elated Scott Bolton, Juno’s principal investigator. “That says it all to me. And I’m so happy to be part of the team that did that. I mean this team has worked so hard and we have such great people. And it’s almost like a dream coming true right here.”

‘Menagerie of possibilities’

Receipt of the radio messages prompted wild cheering at Nasa's Jet Propulsion Laboratory
Receipt of the radio messages prompted wild cheering at Nasa’s Jet Propulsion Laboratory

While the radiation dangers have not gone away, the probe should now be able to prepare its instruments to start sensing what lies beneath Jupiter’s opaque clouds.

Tuesday’s orbit insertion has put Juno in a large ellipse around the planet that takes just over 53 days to complete.

A second burn of the rocket engine in mid-October will tighten this orbit to just 14 days. It is then that the science can really start.

This will involve repeat passes just a few thousand kilometres above the cloudtops.

At each close approach, Juno will use its eight remote sensing instruments – plus its camera – to peer down through the gas planet’s many layers, to measure their composition, temperature, motion and other properties.

A priority will be to determine the abundance of oxygen at Jupiter. This will be bound up in its water.

“How much water Jupiter has tells us a lot about where the planet formed early in the Solar System,” explained team-member Candy Hansen.

“We think that Jupiter may not have formed where it is today, and if it formed further away or closer in – that tells us a lot about how the Solar System in general formed. Because when we look at planets around other stars we see quite a menagerie of possibilities.”

Jupiter is 11 times wider than Earth and 300 times more massive

It takes 12 Earth years to orbit the Sun; a ‘day’ is 10 hours long

In composition it resembles a star; it’s mostly hydrogen and helium

Under pressure, the hydrogen becomes an electrically conducting fluid

This ‘metallic hydrogen’ is likely the source of the magnetic field

Most of the visible cloudtops contain ammonia and hydrogen sulphide

Jupiter’s ‘stripes’ are created by strong east-west winds

The Great Red Spot is a giant storm vortex twice as wide as Earth

The probe will also try to settle old arguments over whether the planet hosts a solid core or whether its gases go all the way down to the centre in an ever more compressed state.

And it will look for the deep swirling sea of liquid metallic hydrogen that theory suggests is the driver behind Jupiter’s immense magnetic field and its spectacular auroras.

Scott Bolton said he wanted particularly to understand more about the Great Red Spot – a long-lived, giant storm.

“I love that Great Red Spot. We see it evolving, and it’s been getting smaller ever since I first got amazed by it, which was when I was a child,” he told reporters.

“The fact that it’s lasted so long – there are records of it going back hundreds of years – means that it must have fairly deep roots.

“It looks a little like a hurricane on the Earth but we know it can’t be working exactly like that because hurricanes on the Earth need an ocean underneath and feed off the liquid and then change when they go on land. At Jupiter, it’s all gas.”

Nasa plans to run Juno through to February 2018, assuming any radiation damage has not made it inoperable by then. The performance of the camera, for example, is expected to degrade rapidly within a few months.

In line with the practice on many previous planetary missions, the probe will be commanded to end its days by ditching into the atmosphere of Jupiter.

This ensures there is no possibility of Juno crashing into and contaminating the gas giant’s large moons, at least one of which, Europa, is considered to have the potential to host microbial life.  (BBC.News)