Uranus.
Mercury and Pluto.
The planet Uranus is tilted "on its side" about 98 degrees to the orbital plane. But all planets in our solar system have some tilt to the side, including Earth which tiles about 23 degrees. (Mercury's tilt is very small.)
The tilt of the Earth's axis relative to the plane of its orbit around the Sun is approximately 23.5 degrees. This tilt is responsible for the changing seasons on Earth as different hemispheres receive varying amounts of sunlight throughout the year.
The tilt of the Earth's axis (about 23.5 degrees) causes the ecliptic plane (the path the Sun appears to take through the sky) to be inclined with respect to the celestial equator. This tilt leads to the changing seasons as the Earth orbits the Sun and causes the ecliptic and celestial equator to intersect at two points, known as the equinoxes.
Earth is tilted at 23.5 degrees from the plane of its orbit around the Sun.
Uranus.
Mercury and Pluto.
The Earth's axis is tilted at an angle of approximately 23.5 degrees from the line perpendicular to the Earth's plane of orbit around the Sun. This tilt is the reason for the changing seasons on Earth as different regions receive varying amounts of sunlight throughout the year.
Neither; the ecliptic, the plane of the Earth's orbit around the Sun, is inclined to the galactic plane by about 60 degrees. The galactic plane is easy to see; it is the path of the Milky Way across the night sky.
It's because the Earth's axis is tilted. Therefore the plane of the equator is tilted (at about 23.5 degrees) away from the plane of the Earth's orbit. Therefore the celestial equator is tilted away from the ecliptic.
This must be Uranus. "On its side" isn't a very scientific way of putting it. It means that the planet's axis is tilted at about 90 degrees (98 degrees actually) from the perpendicular to its orbital plane.
The planet Uranus is tilted "on its side" about 98 degrees to the orbital plane. But all planets in our solar system have some tilt to the side, including Earth which tiles about 23 degrees. (Mercury's tilt is very small.)
The Earth's axis of rotation is at an angle of 23.5 degrees to the plane of the "ecliptic", the orbital plane of the Earth around the Sun. In space, there is no "up" or "down"; for something to be "tilted", it has to be tilted with reference to something else. Since we're here on Earth, it makes sense to use the ecliptic as a common reference plane.
23.5 degrees. That's the angle between the axis of the Earth and a line that is perpendicular to the plane of Earth's orbit around the Sun.
The Moon's orbital plane is tilted about 5 degrees relative to Earth's orbital plane around the Sun. This tilt causes the Moon to appear slightly above or below the ecliptic plane at different points in its orbit.
The tilt of the Earth's axis relative to the plane of its orbit around the Sun is approximately 23.5 degrees. This tilt is responsible for the changing seasons on Earth as different hemispheres receive varying amounts of sunlight throughout the year.