“New Horizons”: To the discovery of Pluto

The space probe New Horizons is almost reaching the nearest distance from Pluto in its fantastic journey. It will be by July 14. Or, for the reader that read this post after this date, it was on July 14… .

It was a long trip of 9 and a half long years with some incidents and adventures. The last incident was recent, with a communication failure and the probe entering its “safe mode”, which caused a huge shock because, in this case, the probe wouldn’t be able to send images. Almost in its final approach of this odyssey,  such issue would be catastrophic! But the genius guys on NASA managed to solve the problem!

The expectation to unveil more mysteries from this celestial body from our solar system is huge. Pluto was considered a planet until 2006, when it became to be designated as a dwarf planet. To me, it was a great injustice! Poor Pluto!

But in fact, what do we know about Pluto so far? Let’s see some relevant data:

• Mass: ≈ 1.305 × 10²² Kg (less than 0,24% that of Earth)
• Volume: ≈ 6.39 x 10⁹ Km³ (roughly 66% that of the Moon)
• Surface area: ≈ 1.665 x 10⁷ Km² (roughly the same surface area as Russia)
• Orbital period: ≈ 247.68 years
• Average orbital speed: ≈ 4.7 Km/s
• Perihelion (Minimum distance from the Sun): 29.657AU (≈ 4,437,000,000 km)
• Aphelion (Maximum distance from the Sun): 39.264AU (≈ 5,874,000,000 km)
• Average temperature: -229ºC (44K)
• Surface pressure: 0.30Pa
• Composition: Nitrogen, methane and carbon monoxid
• Number of satellites: 5 (Charon, Nix, Hydra, Kerbero and Styx)

Pluto’s orbit is highly inclined and eccentric what makes that a small region of Pluto’s orbit lies nearer the Sun than Neptune’s. However, the orbits of these planets are very well defined and there is no risk that these two would ever collide.

For a long time, with the myth of Planet X, many thought that Pluto could be that enigmatic planet that was causing some disturbs to Uranus’ orbit. But this theory fell apart when in 1989 the Voyager 2 sent data that allowed a review of Neptune’s total mass and its gravitational effects on Uranus.

But let’s return to the probe New Horizons. Launched in January of 2006, it started its trip at an amazing speed of about 31,000 miles per hour (≈ 49,890 Km/h). It passed by Mars, Jupiter, Saturn, Uranus and Neptune. Now, after a trip of 3,000,000,000 miles (≈ 4,828,032,000 Km), it will fly within 7,750 miles (≈ 12,472 Km) of Pluto for just a few minutes.

However, it will be enough time to get more detailed photos from this “dwarf” planet that could unveil, for the very first time, some details of the planet’s surface. The probe is also equipped with other scientific equipments that will bring us more detailed informations about the chemical composition and temperatures of the surface of Pluto. And the density, pressure, temperature and other elements present in its atmosphere as well.

From the list of stuff carried by the probe, there are some curious and even bizarre, such as:

• The ashes of Clyde Tombaugh, who discovered Pluto in 1930;
• CD-ROMs with the names of 434,000 people who signed up;
• Two state quarters and two US flags
• A 1991 stamp that says “Pluto: Not Yet Explored”;

The probe will also gather some informations about the Pluto’s moons: Charon, Nix, Hydra, Kerbero and Styx

The larger moon is Charon and interacts with Pluto in a curious way. Thus, there are scientists raising the hypothesis of whether it is a binary system of planets. And the most intriguing are the chaotic orbits  of the 3 smaller moons around this hypothetical binary system. The probe may still gather some informations about the features of the surfaces of the these moons and even about a possible thin atmosphere in Charon.

So, July 14 will be a big day but we will only be able to see the pictures taken by New Horizons on the next day. This because the probe will be too “busy” taking the pictures on July 14 and only after that it will start to transmit them back to Earth and at a very low transmission rate (around 1 kilobit per second, which is about 56 times slower than a 56k modem from the ’90s!) and that takes about 4.5 hours to reach Earth. But it is not a surprise since the probe is about 3 billion miles far away!

After Pluto, scientist hope to keep finding “New Horizons” beyond Pluto in the Kuiper belt, where thousands of small bodies, essentially formed by icy rocks, exist and they could be remnants from the Solar System’s formation. By the way, Pluto itself is on the inner edge of this Kuiper belt and it is the biggest body that exists there.

Let’s wait and see what else will we find out in this far zone of our solar system where we still know so little!

References:

• Wikipedia – Pluto
• Forbes’ article: NASA Loses Contact With New Horizons; Pluto Spacecraft Enters ‘Safe Mode’
• Vox’s article: NASA’s New Horizons mission to Pluto, explained