no. example: Pluto sometimes crosses orbits of other planets and asteroids that arent in the asteroid belt dont.
*NEW EDIT*
YES. The solar system consists of all objects orbiting around the sun. All of them move in elliptical (or ovalish) shaped orbits. This is a basic fact of astronomy. The first answer is totally ridiculous.
the solar system
All the planets have elliptical orbits but Uranus and Neptune have slightly different orbits than other planets on solar system.
The solar system is made up of many plants, dwarf planets, meteorites and asteroids. Asteroids are the celestial objects composed of ice, gases and rocks that orbit the galaxy.
If the objects are in orbit around the sun then they are in the Solar System.
It has been suggested that comets originate in the Oort cloud and then travel in long elliptical orbits around the Sun.
Comets in the solar system follow elliptical orbits around the Sun.
the solar system
Kepler discovered the orbits of the solar system are elliptical.
All the planets have elliptical orbits but Uranus and Neptune have slightly different orbits than other planets on solar system.
The solar system is made up of many plants, dwarf planets, meteorites and asteroids. Asteroids are the celestial objects composed of ice, gases and rocks that orbit the galaxy.
If the objects are in orbit around the sun then they are in the Solar System.
The only orbitals that are very close to circular are those around a system with two stars. All other orbitals have an oval or elliptical shape
It has been suggested that comets originate in the Oort cloud and then travel in long elliptical orbits around the Sun.
Mercury has an elliptical orbit, it is also one of the most eccentric orbits of our solar system.
Comets. Periodic comets have highly eccentric elliptical orbits, with eccentricities.
Long-period comets such as Halley's Comet have elliptical orbits that stretch billions of miles out of the solar system and back again. Other comets have hyperbolic orbits that bring them close once but never again, or at least not for many millions of years.
He provedthat planets moved in elliptical orbits.