New Horizons: One Billion Miles From Pluto

astroengine writes "On Feb. 10, NASA's Pluto-bound New Horizons probe entered the homestretch of its mission. When you are sprinting across the solar system, 'homestretch' is the final 1 billion miles of your journey. That sounds like quite a long stretch! But the half-ton spacecraft has already logged 2 billion miles since its launch in early 2006. That's twice the distance between Earth and Saturn. Though the icy dwarf planet is still three years away from its close encounter, mission scientists call this the Late Cruise phase of the flight."

Comments

Astronomical distances and poetry

[Anonymous Coward]

Whenever I see posts like this, it always makes me think about how big the universe really is. Poets have talked about how far away the stars are and planets and the like. They always talked about hundreds or thousands of miles. Then we get to the real size of the universe and BAM! all of that is now wrong. Even modern poets usually talk in terms of "millions" of miles or kilometers to reach the stars and planets. Makes you seem really small when farther than you can even imagine is not far enough.

Re:Astronomical distances and poetry

[Anonymous Coward]

Whenever I see posts like this, it always makes me think about how big the universe really is. Poets have talked about how far away the stars are and planets and the like. They always talked about hundreds or thousands of miles. Then we get to the real size of the universe and BAM! all of that is now wrong. Even modern poets usually talk in terms of "millions" of miles or kilometers to reach the stars and planets. Makes you seem really small when farther than you can even imagine is not far enough.

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

Re:Astronomical distances and poetry

[SJHillman]

Light-years are too large for this case and the only thing we really have between light-years and miles are AU, which most people don't really get. Granted, they don't understand exactly what a lightyear is either (especially the "I haven't been there in lightyears" crowd), but its even harder to understand what an AU is.

I think the main reason they use miles is people can relate to it. "Grandma's house is 12 miles away. California is 3,000 miles away. Hey, it takes a while to drive to California, I know because I've done it! A billion miles must be reaaallly big". It's a lot harder for Common Joe to relate to AU or lightyears, nevermind trying to explain that 1 billion miles is a little over 5,368 lightseconds.

Re:Astronomical distances and poetry

[monkeyhybrid]

I've been interested in all things 'space' since I was a young kid and consider myself reasonably knowledgeable about the universe, galaxies, star systems, etc, but I still get blown away when thinking about the scale of things some times.

One of the main things I try to put across to people when I talk about space, is just how big it is. Sometimes people can't get their head around the numbers, which is quite understandable seeing as we typically don't have much experience dealing with these kind of measurements, so if I have the chance I will point them to the following links containing fantastic visualisations of such scales. They cover the very big and the very small equally well I think, and are simple and engaging enough for kids to follow too.

Powers of Ten - very interesting short video commissioned by IBM back in 1968.

The Scale of The Universe - interactive flash applet that allows you to zoom in and out of the universe (an updated version of one done a year or two back by the same authors).

Relative size of stars and planets - I have no idea who originally made this set of images but they have propogated around the web over the years and this just happens to be first link to it I found in Google results.

If there's one thing in the second and third links that I think will surprise a lot of people, it's how insanely large the biggest stars are compared to our Sun (in diameter, not necessarily in mass).

Re:Astronomical distances and poetry

[Samantha Wright]

It's really more of a huge amount of line. Cubic light years, of course, are another story.

Re:Astronomical distances and poetry

[Samantha Wright]

Of course I know what an order of magnitude is. It's a secret society of knights that dates back to medieval times, dedicating to raising prime numbers and other common radicals to various exponents. The most famous orders are the Power of Two and the Power of Ten, although some people, mostly retired Russian computer scientists, speak in hushed whispers of the Power of Three (though officially the Power of Three doesn't think they belong, since balanced ternary is quite different from true ternary computing.) The Power of Two used to have two junior orders, the Power of Eight and the Power of Sixteen, but Eight is pretty much defunct these days.

Re:Astronomical distances and poetry

[Ginger Unicorn]

Time isn't infinite. When the universe was at minimum entropy, time began. When the universe reaches maximum entropy, time ends.

Re:Astronomical distances and poetry

[93 Escort Wagon]

Of course I know what an order of magnitude is. It's a secret society of knights that dates back to medieval times, dedicating to raising prime numbers and other common radicals to various exponents.

Yes, and the seal of their order showed ten knights riding one horse, if I remember correctly.

Re:Astronomical distances and poetry

[j35ter]

Oh please, lets keep it simple for the creationists :)

Re:Astronomical distances and poetry

[jackbird]

Two things about The Powers of Ten:

While commissioned by IBM, it was created by the office of Charles and Ray Eames. As in the chair.

An updated, shiner, IMAX version, narrated by Morgan Freeman, was recently created. While prettier, if you watch the two back-to-back on youtube, you can see the science content getting softer and more digestible (not that the original was a tremendously high bar). One exception - the area of the previous order of magnitude is displayed as a circle rather than as a square.

Re:Astronomical distances and poetry

[niktemadur]

From the second Wikipedia link in your post:
"If the universe is finite but unbounded, it is also possible that the universe is smaller than the observable universe. In this case, what we take to be very distant galaxies may actually be duplicate images of nearby galaxies, formed by light that has circumnavigated the universe."

Mind blown.

Re:Obligatory

[Samantha Wright]

It flew through the orbit of Uranus on March 18, 2011.

Scientists at NASA reported that it made a "woosh" noise as it did so, despite the vacuum. They then started a petition to rename Uranus to Urectum.

I'm impressed,

[MSesow]

Blazing out of the sun’s gravitational well at 34,000 miles per hour

That's about like driving from San Francisco to New York City in 5 minutes, or from Madrid to Moscow in a little more than 4 minutes (via Google Maps directions), instead of a couple of days. I'm impressed.

Re:I'm impressed,

[jeffb (2.718)]

Actually, it's about as different from driving as you can get. Stop for just one traffic light between here and Pluto, and see what it does to your mission profile.

Re:I'm impressed,

[Jeng]

Yellow lights should last around 1 second per 10 miles of speed, if the speed limit is 34,000 miles an hour then the yellow light should last 3,400 seconds or a little under an hour.

Re:I'm impressed,

[slew]

FWIW, I think most folks are just thinking about things wrong when they talk about velocity of space vehicles. It's often better to think of things in terms of work and kinetic energy (force x distance). For example, interestingly, once you are in geosync** orbit***, the "escape" speed (aka escape velocity) is even lower than on the ground (since escape_speed ~ sqrt(2GM/r), bigger "r" means lower escape speed), but moving a certain distance and having a certain kinetic energy in the gravitational potential well are more intuitive notions.

Besides, velocity is "generally" relative anyhow ;^) Acceleration is the interesting notion. Standing on earth we are already all going 65,000mph relative to the sun because the earth is in orbit (meaning the earth is balanced between falling into the sun and flinging away). It's only the difficulty of maintaining a chosen velocity on earth where there's lots of friction that warps our perception of velocity. Under constant acceleration in a vaccuum, acheiving high velocity is just a matter of waiting for some time.

**Geosync is just the orbit you have to get to so that the gravitational acceleration matches the centripital acceleration needed to maintain the same relative position on the ground. Of course for a satellite still on the ground, that's easy, static frictional forces provide the needed acceleration to maintain the same relative position on the ground. When the satellite is launched above the ground, there aren't any static frictional forces, so you need to rely on gravity to apply the appropriate gravitational acceleration. If mass and the gravitational constant are invarient, you really only have the radius to play with. You then get whatever "circular" velocity you get at that radius (or you don't stay in orbit very long) w/o applying additional forces over the gravitational force.

***In orbit, you sweep out equal areas in equal time, so in a highly eccentric orbit (or even a parabolic or hyperbolic orbit that you get with gravity assist), you can get really, really, high velocities at some points in the orbit. Of course these types of orbits aren't geosync orbits anymore.

Detailed location data

[dtmos]

A page showing New Horizons' location relative to the planets is here. Detailed ephemeris and other data on the probe can be obtained from NASA's HORIZONS system -- click on Target body "[change]", then enter "-98" in the search box.

The Vertically Challenged Planet

[Oswald McWeany]

Getting to pass close to an object as small as Pluto, (reclassified as I like to say as a "vertically challenged" planet) from 3 billion miles away is impressive. Especially since this is no sitting duck.

This is an object whose velocity is measured in KM per second moving in a very eccentric orbit.

We often take for granted NASA does this and NASA does that- because they have been doing it for decades- but it never ceases to amaze me how we can so accurately target (relatively) small objects that are travelling at such incredible speeds from such mind boggling distances.

Re:The Vertically Challenged Planet

[SJHillman]

You've got a point.

I bet when NASA engineers play beer pong, each cup is moving at a different speed with a different path. And you have to aim from the next city over looking through a spyglass.

fingers crossed

[spirit_fingers]

Given the way NASA's keeps getting slashed, we'll be lucky if there's any money left to analyze the data when it finally does arrive at Pluto.

Re:fingers crossed

[Oswald McWeany]

Nah- Pluto is getting slashed too. A few years ago a planet, now a dwarf planet- soon it will be an asteroid and later it will be reclassified as inter-stellar debris.

You are here

[sakdoctor]

https://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Earth's_Location_in_the_Universe_SMALLER_(JPEG).jpg/1920px-Earth's_Location_in_the_Universe_SMALLER_(JPEG).jpg

The edge of the observable universe is 47,000,000,000 light years away.
Where is your god now?

Re:You are here

[Oswald McWeany]

Probably sitting in front of my fish tank swatting at the glass.

I worship my cat- she is my goddess and empress of the universe. I admit, the question wasn't aimed at me, and not everyone agrees with my deity of choice.

Re:You are here

[Gilmoure]

According to my dogs, I'm the god of good treats and he who knows how to make the adventure box go down the road.

Re:You are here

[willaien]

I feel like the image titled 'pale blue dot' does a better job of illustrating just how... small we are in the grand scheme of things.

http://upload.wikimedia.org/wikipedia/commons/7/73/Pale_Blue_Dot.png

Do a search on youtube for 'Pale Blue Dot' by carl sagan if you want to be humbled.

Re:You are here

[viperidaenz]

Not Albuquerque?

Just some things

[Darth Snowshoe]

Already, NH has prompted much more thorough scrutiny of Pluto, resulting in the discovery of a new (fourth) moon;

http://science.nasa.gov/science-news/science-at-nasa/2011/20jul_p4/

And hey, the program is trying to select a member of the Kuiper Belt to visit beyond Pluto, and they're crowdsourcing the search;

http://www.wired.co.uk/news/archive/2011-06/22/crowd-source-new-horizons-next-destination

Also, there's a New Horizons app in the iPhone App store (don't know if there's an Android version).

9.98 AU from Pluto

[dfcamara]

Distance from Sun (AU): 22.34
Distance from Earth (AU): 23.06
Distance from Pluto (AU): 9.98

IMHO much more sense than billions of miles.

Re:9.98 AU from Pluto

[DanielRavenNest]

The scientifically interesting distance is when it gets close enough to get better data than Hubble did. At perigee, Pluto was at a minimum distance of 28.6 AU from Earth. New Horizons has a much smaller telescope, so it gets 1/20th the resolution as Hubble gets. Therefore it needs to be that much closer, or 1.4 AU away, before it can take better photos. Until then, Earthbound equipment does a better job. That time is around the start of 2015, 6 months before flyby.

Think about this

[eclectro]

If it had not been for the exhorbitant cost of the wars, we could have afforded to build a probe to orbit Pluto rather than just do a flyby.

As it was, New Horizons was largely made possible by a few congressman who pushed specifically for funding for this mission before Pluto's orbit removed it too far away from the sun.

So any "Pioneer" effect?

[wisebabo]

Has there been any indication of the slight change in velocity experienced by (one of?) the Pioneer probes? (I don't know if it was claimed to affect the Voyager probes).

I realize that they think it was due to heating causing a tiny radiation pressure but just wondering.

Also, have they decided if there is a ring system at Pluto to avoid? Any follow on plans to image any specific Kuiper objects?

You know, if they could figure out how to use the main dish for radio-astronometric purposes, it would be fantastic! Although the dish size is very small compared to the ones on the ground, if they could make this work what a fantastic baseline! 100AU! I think they've got enough power to do this (the half life of the plutoniium is 88 years). But maybe they'd need to have an atomic clock on board to pull it off, I doubt they thought of that :(

Re:Pluto is small

[turing_m]

Interestingly enough there are seven moons that are larger than Pluto. Ganymede, Callisto, Titan, the Moon, Io, Europa and Triton.

Re:question

[duh P3rf3ss3r]

The probe started out at roughly our speed and accelerated to 34,471 mph, or about 15.4 km/s. In the absence of a complex acceleration history, the simple, first-order approximation of the probe's average speed over the last 6 years is about 7.7 km/s or about 2.6e-5 c. At that speed, the relativistic effect is about 0.99999999967015470011, meaning that the probe has aged about 62 milliseconds less than you have.