Direct High-Resolution Imaging of Earth-Like Exoplanets

We have surveyed all conventional methods proposed or conceivable for obtaining resolved images of an Earth-like exoplanet.

Generating a 10×10 pixel map of a 1 R_{_Earth} world at 10 pc demands ~0.85 uas angular resolution and photon collection sufficient for SNR >= 5 per “micro-pixel”.

We derived diffraction-limit and photon-budget requirements for: (1) large single-aperture space telescopes with internal coronagraphs; (2) external starshades; (3) space-based interferometry (nulling and non-nulling); (4) ground-based extremely large telescopes with extreme adaptive optics; (5) pupil-densified “hypertelescopes”; (6) indirect reconstructions (rotational light-curve inversion, eclipse mapping, intensity interferometry); and (7) diffraction occultation by Solar System bodies. Even though these approaches serve their primary goals – exoplanet discovery and initial coarse characterization – each remains orders of magnitude away from delivering a spatially resolved image.

In every case, technology readiness falls short, and fundamental barriers leave them 2-5 orders of magnitude below the astrometric resolution and photon-budget thresholds needed to map an Earth analog even on decadal timescales. Ultimately, an in situ platform delivered to <= 0.1 AU of the target could, in principle, overcome both diffraction and photon-starvation limits – but such a mission far exceeds current propulsion, autonomy, and communications capabilities.

By contrast, the Solar Gravitational Lens – providing on-axis gain of ~1e10 and inherent uas-scale focusing once a spacecraft reaches >=550 AU – remains the only near-term, scientifically and technologically viable means to acquire true, resolved surface images and spatially resolved spectroscopy of Earth-like exoplanets in our stellar neighborhood.

Slava G. Turyshev

Comments: 47 pages, 1 table
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); General Relativity and Quantum Cosmology (gr-qc); Space Physics (physics.space-ph)
Cite as: arXiv:2506.20236 [astro-ph.IM] (or arXiv:2506.20236v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2506.20236
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Submission history
From: Slava G. Turyshev
[v1] Wed, 25 Jun 2025 08:27:46 UTC (70 KB)
https://arxiv.org/abs/2506.20236
Astrobiology,