Humans have only set foot on Earth and the Moon; no human has ever visited another planet, but robotic probes have landed on Venus, Mars, and moons like Titan, exploring every planet in our solar system through flybys or orbiters. The Apollo missions landed astronauts on the Moon, while landers and rovers have reached Mars and Venus, but travel to other planets remains a future goal due to technological challenges.
Currently, only robotic landers, rovers and a helicopter have been on Mars. The farthest humans have been beyond Earth is the Moon, under the U.S. National Aeronautics and Space Administration (NASA) Apollo program which ended in 1972.
Not yet, but we've sent rovers, landers, and orbiters to gather the information we'll need to keep future astronauts safe, and with NASA Artemis, we're working on new tech that could one day get humans to Mars.
All three of those stages have been carried out for the Moon, Venus, Mars, Jupiter, Saturn, a comet, and several asteroids. Several Soviet and U.S. robotic spacecraft have landed on Venus and the Moon, and the United States has landed spacecraft on the surface of Mars.
When was Planet X (Planet Nine) discovered? To be clear, Planet X (Planet Nine) has not yet been discovered, and there is debate in the scientific community about whether it exists.
Pluto's highly eccentric, oval-shaped orbit brings it inside Neptune's orbit for a 20-year period every 248 Earth years. This switch, in which Pluto is closer to the Sun than Neptune, happened most recently from 1979 to 1999.
On March 23, 2178, Pluto will complete its first full orbit around the Sun since its discovery. Of the five dwarf planets in the Solar System – including Eris, Ceres, Makemake, and Haumea – Pluto is easily the best-known due to its brief categorization as a regular planet.
Once every 176 years, the giant planets on the outer reaches of the solar system all gather on one side of the sun, and such a configuration was due to occur in the late 1970s.
No extraterrestrial life has yet been scientifically or conclusively detected.
1 hour on Earth can equal 7 years in space (or vice versa) due to time dilation, a concept from Einstein's relativity where strong gravity or extreme speeds slow down time relative to an outside observer, famously depicted in the movie Interstellar on a planet near a black hole where an hour for the crew meant years passing on Earth. It's not about speed alone in orbit (ISS astronauts age slightly slower), but about proximity to immense mass, like a black hole, bending spacetime so drastically that time crawls for those nearby compared to time far away.
Apollo 17 became the last crewed mission to the Moon for an indefinite amount of time. The main reason for this was money. The cost of getting to the Moon was, ironically, astronomical.
Krikalev is sometimes referred to as the "last Soviet citizen," having been aboard Mir during the dissolution of the Soviet Union. With the country that launched him no longer existing, his return was delayed, and he remained in space for 311 days—twice as long as planned.
Return to the Moon
Artemis II, scheduled for launch between February and April sees the return of the first people to the Moon since Apollo 17 in 1972. Three American and one Canadian astronaut will orbit the Moon on a 10 day journey that lays the foundation for lunar landings in the coming years.
K2-18b is about the same temperature as Earth and is in its star's habitable zone. So, it has those things going for it. K2-18b is also nine times more massive than the Earth, but its density is much lower, and we're still not entirely sure why.
In fact, even setting aside our vast undiscovered oceans, it's estimated that over 65% of the Earth's surface remains unexplored. Think of Greenland! Despite our long history of exploration and adventure, humanity still has much more to discover.
The magnitude of this scale factor (nearly 300,000 kilometres or 190,000 miles in space being equivalent to one second in time), along with the fact that spacetime is a manifold, implies that at ordinary, non-relativistic speeds and at ordinary, human-scale distances, there is little that humans might observe that is ...
Alien life, or extraterrestrial life, is hypothetical life that could possibly exist outside of Earth, and which did not originate on Earth. Alien life could range from simple forms of life, such as bacteria and archaea, to intelligent and even sapient beings.
Traveling from one star to another is currently impossible to achieve within a human lifetime. But some projects are designing ways to propel payloads to the nearest star system (Alpha Centauri) using beams of electrons.
Where are Voyager 1 and Voyager 2 Now? Both Voyager 1 and Voyager 2 have reached interstellar space and each continue their unique journey deeper into the cosmos.
Because the Milky Way and its closest neighbors are separated by millions of light-years, any such venture would also require millions of years based on our current understanding of physics. Thus, intergalactic travel is impossible within the human lifetime.
No mate, Pluto didn't disappeared. In August 2006 the International Astronomical Union (IAU) downgraded the status of Pluto to that of "dwarf planet." This means that from now on only the rocky worlds of the inner Solar System and the gas giants of the outer system will be designated as planets.
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We celebrate Earth Day every year on April 22. This reminds us that Earth is our only home. But our actions—pollution, wasting resources, and using plastic—are destroying nature. We can help by turning off lights, using less plastic, planting trees, and spreading awareness.
Pluto, born Jada Amaurie Smith on March 9, 2004, at Atlanta Medical Center, is a rising hip-hop artist from the West Side of Atlanta. A graduate of Washington High School, Pluto began writing freestyles at the age of 14, recording herself rapping over YouTube beats and instrumentals of her favorite songs.