''Whipple'' was a proposed space observatory in the NASA

Discovery Program The Discovery Program is a series of Solar System exploration missions funded by the U.S. National Aeronautics and Space Administration (NASA) through its Planetary Missions Program Office. The cost of each mission is capped at a lower level t ...

. The observatory would try to search for objects in the

Kuiper belt The Kuiper belt ( ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...

and the theorized

Oort cloud The Oort cloud (pronounced or ), sometimes called the Öpik–Oort cloud, is scientific theory, theorized to be a cloud of billions of Volatile (astrogeology), icy planetesimals surrounding the Sun at distances ranging from 2,000 to 200,000 A ...

by conducting blind

occultation An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks f ...

observations. Although the Oort cloud was hypothesized in the 1950s, it has not yet been directly observed. The mission would attempt to detect Oort cloud objects by scanning for brief moments where the objects would block the light of background stars. In 2011, three finalists were selected for the 2016 Discovery Program, and ''Whipple'' was not among them, but it was awarded funding to continue its technological development efforts.

Description

''Whipple'' would orbit in a

halo orbit A halo orbit is a periodic, non-planar orbit associated with one of the L1, L2 or L3 Lagrange points in the three-body problem of orbital mechanics. Although a Lagrange point is just a point in empty space, its peculiar characteristic is th ...

around the Earth–Sun and have a photometer that would try to detect Oort cloud and

objects (KBOs) by recording their transits of distant stars. It would be designed to detect objects out to . Some of the mission goals included directly detecting the Oort cloud for the first time and determining the outer limit of the Kuiper belt. ''Whipple'' would be designed to detect objects as small as a kilometer (half a mile) across at a distance of . Its telescope would need a relatively wide

field of view The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to elec ...

and fast recording cadence to capture transits that may last only seconds. In 2011, ''Whipple'' was one of three proposals to win a technology development award in a Discovery Program selection. The design proposed was a

catadioptric A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses ( dioptrics) and curved mirrors ( catoptrics). Catadioptric combinations are used in focusing systems such as searchlig ...

Cassegrain telescope The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to th ...

with a 77-centimeter aperture (30.3 inches). It would have a wide field of view with a fast read-out CMOS detector to achieve the desired time and photometric sensitivity. The smallest KBO yet detected was discovered in 2009 by poring over data from the

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

fine guidance sensors Fine may refer to: Characters * Fran Fine, the title character of ''The Nanny'' * Sylvia Fine (''The Nanny''), Fran's mother on ''The Nanny'' * Officer Fine, a character in ''Tales from the Crypt'', played by Vincent Spano Legal terms * Fine (p ...

. Astronomers detected a transit of an object against a distant star, which, based on the duration and amount of dimming, was calculated to be a KBO about in diameter. It has been suggested that the

Kepler space telescope The Kepler space telescope is a defunct space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orb ...

may be able to detect objects in the Oort cloud by their occultation of background stars.

References

External links

Whipple: Exploring the Solar System Beyond Neptune Using a Survey for Occultations of Bright Stars
{{Planetary Missions Program Office, Discovery=y Discovery program proposals Oort cloud Cancelled spacecraft Space telescopes Stellar occultation

Description

See also

References

External links