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The James Webb Space Telescope (JWST) is a large (6.6 m), cold (

The orbital evolution of more than 22000 Jupiter-crossing objects under the gravitational influence of planets was investigated. We found that the mean collision probabilities of Jupiter-crossing objects (from initial orbits close to the orbit of a comet) with the terrestrial planets can differ by more than two orders of magnitude for different comets. For initial orbital elements close to those of some comets (e.g., 2P and 10P), about 0.1% of objects got Earth-crossing orbits with semi-major axes a < 2 AU and moved in such orbits for more than a Myr (up to tens or even hundreds of Myrs). Results of our runs testify in favor of at least one of these conclusions: (1) the portion of 1-km former trans-Neptunian objects (TNOs) among near-Earth objects (NEOs) can exceed several tens of percent, (2) the number of TNOs migrating inside the solar system could be smaller by a factor of several than it was earlier considered, (3) most of 1-km former TNOs that had got NEO orbits disintegrated into mini-comets and dust during a smaller part of their dynamical lifetimes if these lifetimes are not small.

Following Mather et al. (1999) we describe a concept for a future space mission called SPECS, a spatial and spectral Michelson interferometer with Hubble Telescope-class angular resolution and sensitivity that operates in the far infrared and submillimeter spectral range. SPECS enables detailed studies of the physical conditions in high-redshift galaxies and has the potential to revolutionize our understanding of galaxy formation and evolution.

The Next Generation Space Telescope (NGST) is a key element in NASA’s Origins program. The primary goals for the NGST are observing the origins of stars, galaxies, and the elements that are necessary for life. To reach those goals, the telescope must work in the near and mid-infrared — at wavelengths where the Earth’s atmosphere outshines the distant galaxies by up to 8 orders of magnitude. NASA, industry, US astronomers and international collaborators have completed the initial feasibility study and have begun the development of the technologies required to make the mission affordable and ready to launch by 2007.

The Next Generation Space Telescope (NGST) is under study by NASA as a successor to the Hubble Space Telescope (HST), and the infrared missions SIRTF (Space Infrared Telescope Facility), SOFIA (Stratospheric Observatory for Infrared Astronomy), and ISO (Infrared Space Observatory). It would have an aperture > 4 m, optimized for 1–5 μm, with a goal of 8 m and 0.5 – 20 µm. It would be radiatively cooled and would be launched on an Atlas HAS to the Lagrange Point L2 around 2006. At wavelengths longer than a few µm, it offers a speed advantage of the order of 106 over a large ground based telescope.

Editorial Comments: The final slot of the Conference Program was the very lively ‘Eyes to the Future’ session. Our four panelists were seated in the front of the lecture theatre, facing the audience. A television crew hired by the University’s TV unit recorded the entire session for us; the TV tape was then transcribed into LATEX. Appearing in square brackets […] below are occassional editorial comments - added at times for clarity and continuity of speech.

The Cosmic Background Explorer (COBE) was developed by NASA Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early universe. It also measured emission from nearby sources such as the stars, dust, molecules, atoms, ions, and electrons in the Milky Way, and dust and comets in the Solar System. It was launched 18 November 1989 on a Delta rocket., carrying one microwave instrument and two cryogenically cooled infrared instruments. The Far Infrared Absolute Spectrophotometer (FIRAS) mapped the sky at wavelengths from 0.01 to 1 cm, and compared the CMBR to a precise blackbody. The spectrum of the CMBR differs from a blackbody by less than 0.03%. The Differential Microwave Radiometers (DMR) measured the fluctuations in the CMBR originating in the Big Bang, with a total amplitude of 11 parts per million on a 10° scale. These fluctuations are consistent with scale-invariant primordial fluctuations. The Diffuse Infrared Background Experiment (DIRBE) spanned the wavelength range from 1.2 to 240 μm and mapped the sky at a wide range of solar elongation angles to distinguish foreground sources from a possible extragalactic Cosmic Infrared Background Radiation (CIBR). In this paper we summarize the COBE mission and describe the results from the FIRAS instrument. The results from the DMR and DIRBE were described by Smoot and Hauser at this Symposium.

Cosmic microwave and infrared background radiation (CMBR and CIBR) measurements in the near future have the potential to greatly advance our knowledge of the early universe. New instrument and space technology will soon enable much better measurements of both.

The Cosmic Background Explorer (COBE) was developed by NASA Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early universe. It also measured emission from nearby sources such as the stars, dust, molecules, atoms, ions, and electrons in the Milky Way, and dust and comets in the Solar System. It was launched 18 November 1989 on a Delta rocket, carrying one microwave instrument and two cryogenically cooled infrared instruments. The Differential Microwave Radiometers (DMR) measured the fluctuations in the CMBR originating in the Big Bang, with a total amplitude of 11 parts per million on a 10° scale. These fluctuations are consistent with scale-invariant primordial fluctuations. The Far Infrared Absolute Spectrophotometer (FIRAS) mapped the sky at wavelengths from 0.01 to 1 cm, and compared the CMBR to a precise blackbody. The spectrum of the CMBR differs from a blackbody by less than 0.03%. The Diffuse Infrared Background Experiment (DIRBE) spanned the wavelength range from 1.2 to 240 μm and mapped the sky at a wide range of solar elongation angles to distinguish foreground sources from a possible extragalactic Cosmic Infrared Background Radiation (CIBR).

The COBE1 satellite was developed by the NASA Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early universe, to the limits set by our astrophysical environment. It was launched on November 18,1989 and carried three instruments, a Far Infrared Absolute Spectrophotometer (FIRAS) to compare the spectrum of the cosmic microwave background radiation with a precise blackbody, a Differential Microwave Radiometer (DMR) to map the cosmic radiation precisely, and a Diffuse Infrared Background Experiment (DIRBE) to search for the cosmic infrared background radiation. The cosmic microwave background spectrum was measured with a precision of 0.03% (Mather et al., 1994), the spectrum of the cosmic dipole was measured (Fixsen et al., 1994), the background was found to have intrinsic anisotropy for the first time, at a level of a part in 105 (Smoot et al. , 1992 and Bennett et al , 1994a), and absolute sky brightness maps from 1.25 µm to 240 µm have been obtained to carry out the search for the cosmic infrared background (Hauser et al. , 1991). As planned, COBE ceased collecting science data on December 23, 1993. The instruments that required cryogenic cooling (DIRBE, at wavelengths longward of 3.5 µm, and FIRAS) previously had stopped operating when the supply of liquid helium was exhausted on 21 September 1990. A more complete description of COBE is given elsewhere (Boggess et al. , 1992).

NASA Goddard Space Flight Center developed the Cosmic Background Explorer (COBE) satellite to observe the diffuse microwave and infrared radiation from early universe. It also measured diffuse emission from galactic stars, dust, molecules, atoms, ions, and electrons, as well as thermal emission and reflected sunlight from interplanetary dust and comets. It was launched Nov. 18, 19898 by a Delta rocket and carried three instruments. The Differential Microwave Radiometers (DMR) mapped the anisotropy of the cosmic microwave background radiation (CMBR), found a total anisotropy of 11 parts per million on a 10° angular scale, and showed that its angular distribution agrees with scale-invariant primordial fluctuations. The Far Infrared Absolute Spectrophotometer (FIRAS) compared the CMBR with a precise blackbody and showed that the deviations are less than 0.03%. The Diffuse Infrared Background Experiment (DIRBE) mapped the sky at 10 infrared wavelengths and at a wide range of angles from the Sun to enable determination of an extragalactic Cosmic Infrared Background radiation (CIB).

The Cosmic Background Explorer or COBE 1, NASA’s first space mission devoted primarily to cosmology, carries three scientific instruments to make precise measurements of the spectrum and anisotropy of the cosmic microwave background (CMB) radiation on angular scales greater than 7°and to conduct a search for a diffuse cosmic infrared background (CIB) radiation with 0.7° angular resolution. The observing strategy is designed to minimize and allow determination of systematic errors that could result from spacecraft operations, the local environment of the spacecraft, and emissions from foreground astrophysical sources such as the Galaxy and the solar system. Data from the Far-InfraRed Absolute Spectrophotometer (FIRAS) show that the spectrum of the CMB is that of a blackbody of temperature T= 2.73 ± 0.06 K, with no deviation from a blackbody spectrum greater than 0.25% of the peak brightness. Data from the first year of the Differential Microwave Radiometers (DMR) show statistically significant CMB anisotropy. The anisotropy is consistent with a scale invariant primordial density fluctuation spectrum and with the gravitational potential variations required to cause the observed present day structure. Infrared sky brightness measurements from the Diffuse InfraRed Background Experiment (DIRBE) provide new conservative upper limits to the CIB. Extensive modeling of solar system and galactic infrared foregrounds is required for further improvement in the CIB limits.

The Cosmic Background Explorer (COBE)1 was launched in November 1989. Its scientific objectives are to search for spatial anisotropics and spectral distortions in the 2.7 K cosmic microwave background (CMB) radiation, to detect the diffuse infrared background radiation from the first objects to form after the Big Bang, and to study all other sources of diffuse radiation from 1 micron to 1 centimeter. These other sources include interplanetary and interstellar dust, hot electrons in the Galaxy, faint stars in the Galaxy, and possibly IR galaxies and hot gas in galaxy clusters. To map these primeval and local sources, the three scientific instruments on COBE scan the sky repeatedly, building up signal-to-noise statistics until the data are limited only by the astrophysical environment. The three instruments are the DIRBE (Diffuse Infrared Background Experiment) covering 1 to 300 micron with a 10 band filter photometer and a 0.7° beamwidth; the FIRAS (Far Infrared Absolute Spectrophotometer) covering 100 microns to 1 cm with an absolutely calibrated polarizing Michelson interferometer with a 5 percent spectral resolution and a 7° beamwidth; and the DMR (Differential Microwave Radiometers) covering 31.5,53, and 90 GHz with 7° beamwidth. COBE is described further elsewhere (see Gulkis et al., 1990).

The Diffuse Infrared-Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) satellite is a 10-band absolute photometer covering the wavelengths 1–300 microns using photovoltaic, photoconductive, and bolometric detectors. The input is via a 19-cm, off-axis, highly-baffled Gregorian telescope, with the detectors located at a pupil plane so they share the same field of view (0.7 × 0.7 degrees). The whole assembly is mounted inside a 1.4 K super-fluid, liquid-He dewar, which is shared with the Far Infrared Absolute Spectrometer (FIRAS) instrument. Each day half of the sky is surveyed, as the line-of-sight of the DIRBE is canted 30 degrees to the COBE spin axis. The whole sky is fully observed in 6 months, as the spin axis precesses at about 1 degree per day. At present each sky pixel has been observed at least once. The basic findings on the general brightness of the sky — Zodiacal light and galaxy — are provided, as well as a synopsis of the advantages and disadvantages associated with a space-borne observatory. The relationship of our experience and findings with respect to possible future missions and their scientific goals is presented.