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  2. Orbital speed - Wikipedia

    en.wikipedia.org/wiki/Orbital_speed

    In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter (the combined center of mass) or, if one body is much more massive than the other bodies of the system combined, its speed relative to the center of mass of the most massive body.

  3. Standard asteroid physical characteristics - Wikipedia

    en.wikipedia.org/wiki/Standard_asteroid_physical...

    Infra-red observations are commonly combined with albedo to measure the temperature more directly. For example, L.F. Lim et al. does this for 29 asteroids. [9] These measurements are contingent for a particular day of observation. and the asteroid's surface temperature will change in a regular way depending on its distance from the Sun.

  4. 2021 PH27 - Wikipedia

    en.wikipedia.org/wiki/2021_PH27

    Being so close to the Sun, at perihelion the asteroid is moving at 106 km/s (240,000 mph). [5] The relativistic perihelion shift of this object is 1.6 times that of Mercury, which is 42.9 arcseconds per century. [8] With an observation arc over 4 years, the orbit quality of 2021 PH 27 is well secured, with an uncertainty parameter of 3. [4]

  5. Asteroid - Wikipedia

    en.wikipedia.org/wiki/Asteroid

    The Amors have orbits strictly outside Earth's orbit: an Amor asteroid's perihelion distance (q) is greater than Earth's aphelion distance (1.017 AU). Amor asteroids are also near-earth objects so q < 1.3 AU. In summary, 1.017 AU < q < 1.3 AU. (This implies that the asteroid's semi-major axis (a) is also larger than 1.017 AU.)

  6. Do You Need to Worry About an Asteroid Hitting Earth? - AOL

    www.aol.com/news/worry-asteroid-hitting-earth...

    The space rock does not remotely pose an existential threat to life on Earth. It measures 130 to 300 feet across , a pebble compared to the asteroid that killed the dinosaurs, which is estimated ...

  7. Asteroid impact prediction - Wikipedia

    en.wikipedia.org/wiki/Asteroid_impact_prediction

    The missed asteroids do tend to be small, and missing small asteroids is relatively unimportant. By contrast, missing a large day-side impacting asteroid is highly problematic, with the unpredicted mid-size Chelyabinsk meteor providing a mild real-life example. In order to assess the effectiveness for detecting the (rare) larger asteroids which ...

  8. Asteroids safely fly by Earth all the time. Here’s why ...

    www.aol.com/asteroids-safely-fly-earth-time...

    Here's what to know about Apophis and how space agencies hope to protect Earth from other asteroids like it. Apophis to make 2029 flyby to Earth Apophis is projected to pass within 20,000 miles of ...

  9. Astronomical unit - Wikipedia

    en.wikipedia.org/wiki/Astronomical_unit

    Distance light travels in one Julian year (365.25 days) — Oort cloud: 75 000: ± 25 000: Distance of the outer limit of Oort cloud from the Sun (estimated, corresponds to 1.2 light-years) — Parsec: 206 265 — One parsec. The parsec is defined in terms of the astronomical unit, is used to measure distances beyond the scope of the Solar ...