Where is the furthest humans have sent probes in space? To the nearest star to our Sun

To the Moon

Outside the edges of the solar system

To Mars

That's not a simple question, and it doesn't have a simple answer.

The two Voyager spacecraft have been flying for about 43 years now.

They left the "heliosphere" about 2 years ago (in November 2018), and are now about 10.9 billion miles from Earth.

Mission controllers can still communicate with them, but it takes radio signals almost 17 hours to reach either one of the spacecraft from Earth.

(And another 17 hours if it has anything to answer back.  That's a day and a half to do a "How are you ?" . . . . . "I'm OK.".)

But wait !  

The boundary of the solar system is considered to be beyond the outer edge of the "Oort Cloud", a collection of small objects that are still under the influence of the Sun's gravity. The thickness of the Oort Cloud is not exactly known, but it's estimated to begin at about 93 billion miles from the Sun, and to extend maybe as far as 9,300 billion miles from the sun.  It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.

So even though the Voyager spacecraft are the farthest man-made objects away from Earth, and have been sailing along for 43 years, neither of them is anywhere near leaving the solar system yet.

Yes, we've sent artificial probes past the Sun, the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, several asteroids, several comets, and past the Kuiper belt, we're still thousands of years from leaving the solar system, and millions of years from reaching the next nearest star ... even if the Voyagers don't get pulverized into dust by meteoroids and radiation before they get there.

a. are

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y